Osisko Infill Drilling Continues to Intersect High-Grade at Lynx

Highlights from new infill drilling results at Lynx include: 84.6 g/t Au over 11.8 metres in OSK-W-19-909-W11; 429 g/t Au over 2.2 metres in OSK-W-19-934-W2; 149 g/t Au over 2.2 metres in WST-19-0134; 121 g/t Au over 2.3 metres in OSK-W-19-1857-W2; 119 g/t Au over 2.0 metres in WST-19-0139; 86.9 g/t Au over 2.7 metres in WST-19-0145 and 63.2 g/t Au over 2.3 metres in WST-19-0138. Maps showing hole locations and full analytical results are available at www.osiskomining.com.

Osisko President and Chief Executive Officer John Burzynski commented: “We continue to be impressed by the gold mineralization we are encountering in the infill and expansion drilling at Lynx.  We are very optimistic that we will be able to add significant ounces as we progress with resource drilling and exploration of the Windfall deposit.”

Surface Drilling

Underground drilling

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See "Quality Control and Reporting Protocols" below.

Surface Drilling

Underground drilling

OSK-W-18-1539 intersected 4.46 g/t Au over 2.2 metres. Mineralization includes up to 10% disseminated pyrite, 4% pyrite stringers and clusters, 3% pyrite in ptygmatic tourmaline veinlets and 2% interstitial pyrite within a silica, sericite and fuchsite altered rhyolite and a sericite and chlorite altered andesite.

OSK-W-18-1745 intersected two intervals: 5.96 g/t Au over 2.5 metres and 3.98 g/t Au over 5.7 metres. The first interval contains 7% disseminated and dismembered stringer pyrite in a moderate silica and sericite altered andesite at the contact with a porphyritic felsic dike. The second interval contains up to 15% disseminated, clustered, and stringer pyrite in quartz-tourmaline and quartz-carbonate veins at the contact between a sericite and silica altered rhyolite and a sericite, silica and fuchsite altered gabbro.

OSK-W-19-909-W7 intersected 14.3 g/t Au over 2.1 metres. Mineralization includes 1% pyrite stringers in a strong silica, moderate sericite and weak fuchsite altered porphyritic felsic dike.

OSK-W-19-909-W11 intersected 84.6 g/t Au over 11.8 metres. Mineralization includes local visible gold, up to 15% pyrite stringers and clusters, and trace chalcopyrite and sphalerite within a strongly sericitized and silicified gabbro with moderate fuchsite alteration.

OSK-W-19-934-W2 intersected three intervals: 32.9 g/t Au over 3.0 metres, 16.9 g/t Au over 2.0 metres and 429 g/t Au over 2.2 metres. The first interval contains 4% pyrite stringers and clusters hosted in a moderate sericite-silica altered and bleached rhyolite. The second interval contains 5% interstitial pyrite in a moderate chlorite-silica altered rhyolite with breccia texture. The third interval contains 1% local visible gold veinlets and clusters and 5% pyrite within a smoky quartz-tourmaline crustiform vein hosted in a strong sericite and silica altered rhyolite at the contact with a bleached andesite.

OSK-W-19-1181-W8 intersected 8.31 g/t Au over 2.3 metres and 13.1 g/t Au over 2.3 metres. The first interval contains 5% disseminated, stringer, and clustered pyrite, and trace chalcopyrite in quartz-carbonate veinlets with local visible gold within a strong silica and moderate sericite altered gabbro. The second interval contains up to 30% disseminated, clustered and locally semi-massive pyrite in a strong silica altered rhyolite with moderate sericite alteration at the contact with a mafic volcanic unit.

OSK-W-19-1181-W9 intersected 48.2 g/t Au over 2.6 metres. Mineralization includes up to 5% disseminated pyrite, 3% pyrite clusters and trace chalcopyrite with pervasive-silica flooding and local sericite alteration hosted in a gabbro at the contact with a sericitized rhyolite.

OSK-W-19-1746-W1 intersected 19.0 g/t Au over 2.5 metres and 17.0 g/t Au over 2.4 metres. The first interval contains local visible gold with 20% pyrite filling millimeter to centimeter scale tourmaline fractures with massive pervasive silica flooding hosted in a porphyritic felsic intrusion. The second interval contains local visible gold with 15% disseminated or fracture-filling pyrite and 1% sphalerite in a smoky quartz vein. Both intervals are hosted is a silicified rhyolite with local fragmental texture.

OSK-W-19-1835 intersected 5.06g/t Au over 2.4 metres.  Mineralization includes 1% disseminated pyrite with quartz veins in a weak sericite altered porphyritic felsic dike.

OSK-W-19-1835-W1 intersected 4.28g/t Au over 2.1 metres and 3.26 g/t Au over 2.2 metres. The first interval contains 2% pyrite stringers, 10% semi-massive pyrite within a sericite and silica altered porphyritic felsic dike. The second interval contains 3% pyrite within pervasive silica flooding, 1% fracture filling pyrite and 1% disseminated pyrite in a bleached porphyritic felsic dike.

OSK-W-19-1857-W2 intersected 121g/t Au over 2.3 metres. Mineralization includes local visible gold in quartz-carbonate veins, 10% disseminated, clustered, and stringer pyrite ± tourmaline, and trace chalcopyrite within a rhyolite with strong silica and moderate sericite alteration.

OSK-W-19-1875 intersected 5.76 g/t Au over 2.7 metres. Mineralization includes 6% disseminated pyrite and 1% pyrite in quartz-carbonate veins hosted in a sericitized andesite.

OSK-W-19-1880 intersected 4.07 g/t Au over 2.2 metres. Mineralization includes 3% pyrite-tourmaline stringers and trace disseminated pyrite with pervasive silica flooding and tourmaline ptygmatic veins at the contact between a porphyritic felsic dike, a rhyolite and a gabbro.

OSK-W-19-1900 intersected 9.41 g/t Au over 2.0 metres. Mineralization includes 3% pyrite stringers with local silicification hosted in a weak to moderate sericite and silica altered porphyritic felsic dike.

OSK-W-19-1921-W1 intersected two intervals in Lynx: 19.9 g/t Au over 2.1 metres and 4.01 g/t Au over 2.4 metres. The first interval contains local visible gold with 5% disseminated and stringer pyrite in a smoky quartz vein hosted in a gabbro with local and strong pervasive silica flooding. The second interval contains 4% pyrite stringers, 2% pyrite clusters and 20% quartz-carbonate veins in a moderate chlorite altered gabbro with weak sericite, silica and fuchsite alteration.

OSK-W-19-1921-W2 intersected 7.83 g/t Au over 3.5 metres. Mineralization includes 3% pyrite-tourmaline stringers and trace disseminated pyrite with quartz-tourmaline veins in a weakly sericitized and silicified rhyolite.

OSK-W-19-1932 intersected 31.3 g/t Au over 4.1 metres. Mineralization includes 5% pyrite clusters and 2% pyrite stringers within a local quartz-carbonate vein hosted in a weak fuchsite, moderate chlorite and sericite altered gabbro.

OSK-W-19-1932-W1 intersected 3.40g/t Au over 2.2 metres. Mineralization includes 5% pyrite clusters and 1% pyrite stringers at the contact between a weakly sericitized and moderately silicified rhyolite and a weak silica-chlorite and moderate sericite altered gabbro.

OSK-W-19-1932-W2 intersected four intervals: 10.2 g/t Au over 2.0 metres, 86.5 g/t Au over 2.0 metres, 85.8 g/t Au over 2.1 metres and 29.6 g/t Au over 2.0 metres. The first interval contains 4% pyrite stringers and clusters in a sericitized and silicified gabbro with moderate fuchsite alteration. The second interval contains 5% pyrite clusters and stringers in a fragmental felsic unit with strong local silica and fuchsite alteration. The third and fourth intervals contain local visible gold and 3% pyrite with pervasive silica flooding within a sericitized and silicified rhyolite.

OSK-W-19-1939 intersected 6.44 g/t Au over 2.0 metres and 18.7 g/t Au over 2.4 metres. Mineralization in both intervals contains local visible gold, 5% disseminated, stringer, and clustered pyrite with ptygmatic tourmaline veinlets hosted in a moderately sericitized and weakly silicified rhyolite.

OSK-W-19-1942 intersected 11.3 g/t Au over 2.3 metres. Mineralization includes local visible gold, 2% disseminated and stringer pyrite with local tourmaline with pervasive silica flooding hosted in a moderate sericite and weak silica altered rhyolite.

OSK-W-19-1942-W1 intersected 3.08g/t Au over 2.0 metres. Mineralization includes 4% pyrite stringers and clusters and trace sphalerite and chalcopyrite hosted in a moderate sericite and silica altered rhyolite at the contact with a moderate chlorite altered gabbro.

OSK-W-19-1949 intersected three intervals: 3.19 g/t Au over 2.0 metres, 11.5 g/t Au over 3.7 metres and 31.3 g/t Au over 3.3 metres.  The first interval contains local visible gold and smoky quartz veins with up to 8% pyrite in a porphyritic felsic dike with weak fuchsite and carbonate alteration. The second interval contains 4% pyrite stringers and clusters, 2% interstitial sphalerite and trace chalcopyrite with pervasive silica flooding, quartz carbonate veins and ptygmatic tourmaline veins hosted in a silicified felsic intrusion at the contact with a sericitized rhyolite. The third interval contains up to 10% pyrite with brecciated smoky quartz veins hosted in a moderate sericite and weak silica altered rhyolite.

WST-19-0088 intersected 4.67g/t Au over 2.1 metres. Mineralization includes 3% pyrite clusters and stringers and 1% disseminated pyrite within a chloritized fragmental andesite unit. WST-19-0088 was drilled from underground drill station AN-190-155-N located 190 metres below surface from section 2300E.

WST-19-0112 intersected 17.2 g/t Au over 2.3 metres. Mineralization includes 7% clustered and disseminated pyrite with intense pervasive silica flooding in a silicified porphyritic felsic dike and a rhyolite. WST-19-0112 was drilled from underground drill station RA-180-190-E located 180 metres below surface from section 3450E.

WST-19-0119 intersected 3.07 g/t Au over 2.0 metres. Mineralization includes 2% pyrite clusters, trace disseminated pyrite and 10% quartz-tourmaline in a weak silica and sericite altered rhyolite. WST-19-0119 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0123 intersected 6.77 g/t Au over 2.0 metres. Mineralization includes 3% pyrite clusters with pervasive silica flooding within a weak sericite altered rhyolite. WST-19-0123 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0127B intersected 21.9 g/t Au over 3.1 metres. Mineralization includes 3% clustered and disseminated pyrite, local pyrite-tourmaline stringers and trace sphalerite with smoky pervasive silica flooding and local pyritized fragments. Local visible gold is observed with pyrite within a sericitized breccia hosted in a sericitized rhyolite. WST-19-0127B was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0131 intersected three intervals: 13.8 g/t Au over 2.4 metres, 92.1 g/t Au over 2.5 metres and 12.9 g/t Au over 2.1 metres. Mineralization in all three intervals contains local visible gold with 2% pyrite in pervasive silica flooding zone and trace sphalerite in a sericitized and silicified fragmental felsic unit. WST-19-0131 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0133 intersected 12.9 g/t Au over 6.2 metres. Mineralization includes local visible gold, 1% pyrite clusters with 2% pervasive silica flooding. Mineralization is directly related to silica fracture filling. The interval is hosted in a sericitized fragmental felsic unit. WST-19-0133 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0134 intersected three intervals: 10.8 g/t Au over 2.1 metres, 10.5 g/t Au over 2.2 metres and 149 g/t Au over 2.2 metres. The first and second intervals contain local visible gold, 2% disseminated, clustered, and stringer pyrite with pervasive silica flooding hosted in a sericitized fragmental felsic unit. The third interval contains local visible gold, 7% pyrite stringers and trace sphalerite with pervasive silica flooding hosted in a weakly sericitized and moderately silicified porphyritic rhyolite. WST-19-0134 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0137 intersected 10.4 g/t Au over 2.0 metres. Mineralization includes trace disseminated pyrite in quartz-carbonate veins in a moderated chlorite altered and faulted rhyolite. WST-19-0137 was drilled from underground drill station AN-195-265-S located 195 metres below surface from section 3500E.

WST-19-0138 intersected three intervals: 5.52 g/t Au over 2.4 metres, 3.04 g/t Au over 2.0 metres and 63.2 g/t Au over 2.3 metres. The first interval contains trace pyrite with quartz-tourmaline veins in a moderate chlorite-sericite altered and fragmental felsic unit. The second interval contains 4% pyrite clusters with two intense pervasive silica flooding zones with fragments of felsic intrusion, volcanics, tourmaline and pyrite at the contact with a sericitized rhyolite. The third interval contains traces of disseminated and clustered pyrite with 30% quartz-carbonate veins at the contact between a rhyolite and a chloritized gabbro. WST-19-0138 was drilled from underground drill station AN-195-265-S located 195 metres below surface from section 3500E.

WST-19-0139 intersected 119 g/t Au over 2.0 metres. Mineralization includes local visible gold and 15% pyrite within smoky quartz vein or pervasive silica flooding hosted at the strongly silicified contact between a felsic porphyritic intrusion and a rhyolite. WST-19-0139 was drilled from underground drill station AN-195-265-S located 195 metres below surface from section 3500E.

WST-19-0140 intersected three interval: 7.58 g/t Au over 2.0 metres, 9.00 g/t Au over 4.3 metres and 10.3 g/t Au over 2.6 metres. The first interval contains trace pyrite stringers, 2% disseminated pyrite and trace sphalerite with irregular quartz-carbonate-tourmaline veins hosted in sericitized fragmental felsic unit at the contact with a sericitized rhyolite. The second interval contains 1% sphalerite clusters and 7% pyrite within smoky veins hosted in weakly silicified, sericitized and fuchsitized rhyolite. The third interval contains 1% disseminated and clustered pyrite with intense silica flooding hosted in a silicified porphyritic felsic dike at the contact with a sericitized and silicified rhyolite. WST-19-0140 was drilled from underground drill station AN-195-265-S located 195 metres below surface from section 3500E.

WST-19-0145 intersected 86.9 g/t Au over 2.7 metres. Mineralization includes local visible gold, trace sphalerite and 1% disseminated pyrite with quartz-tourmaline-carbonate veins within a silica and carbonate altered rhyolite. WST-19-0145 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

WST-19-0146 intersected four intervals: 4.84 g/t Au over 2.0 metres, 3.51 g/t Au over 2.0 metres, 63.7 g/t Au over 2.0 metres and 5.60 g/t Au over 4.0 metres. The first interval contains 5% semi-massive pyrite in a 10 centimetres-wide band, 1% pyrite clusters, and 1% pyrite-tourmaline stringers in a silica altered rhyolite. The second interval contains 30% pyrite with quartz-tourmaline veins in a sericitized rhyolite. The third interval contains trace disseminated pyrite in stockwork in a weakly sericitized rhyolite. The fourth interval contains trace pyrite in a breccia with tourmaline in a moderate chlorite, silica and sericite altered gabbro. WST-19-0146 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

WST-19-0149 intersected 106 g/t Au over 2.2 metres. Mineralization includes local visible gold, 3% dismembered pyrite stringers, 2% pyrite clusters, trace sphalerite and chalcopyrite with weakly fuchsitized pervasive silica flooding hosted in a moderate sericite-silica altered rhyolite. WST-19-0149 was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0150B intersected 17.7g/t Au over 2.1 metres and 33.5 g/t Au over 2.1 metres in Lynx. Mineralization in both intervals contains local visible gold, 3% pyrite stringers and clusters and trace sphalerite with pervasive silica flooding and quartz-carbonate veinlets hosted in a sericite and silica altered rhyolite. WST-19-0150B was drilled from underground drill station RE-195-265-O located 195 metres below surface from section 3475E.

WST-19-0153 intersected 15.9 g/t Au over 4.5 metres. Mineralization includes up to 5% pyrite stringers hosted in a moderately silicified felsic intrusion with intrusive, volcanic, tourmaline and pyrite fragments. WST-19-0153 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

WST-19-0156 intersected 10.4 g/t Au over 2.9 metres and 21.3 g/t Au over 2.5 metres. Mineralization includes up to 15% pyrite associated with pervasive silica flooding hosted in a strongly silicified rhyolite. WST-19-0156 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

WST-19-0157 intersected 3.86 g/t Au over 2.0 metres. Mineralization includes 3% pyrite with pervasive silica flooding in a moderate sericite, silica and chlorite altered gabbro. WST-19-0157 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

WST-19-0158 intersected 10.3 g/t Au over 2.0 metres and 3.10 g/t Au over 2.0 metres. The first interval contains 5% pyrite stringers and clusters with pervasive silica flooding within a moderate sericite, silica and fuchsite altered gabbro. The second interval contains 3% pyrite clusters at the contact between a rhyolite and a strongly sericitized, bleached and fuchsite altered gabbro. WST-19-0158 was drilled from underground drill station BM-200-285-S located 200 metres below surface from section 3525E.

Qualified Person
The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Louis Grenier, M.Sc.A., P.Geo. (OGQ 800), Project Manager of Osisko's Windfall Lake gold project, who is a "qualified person" as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101").

Quality Control and Reporting Protocols
True width determination is estimated at 55-80% of the reported core length interval for the zone. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Reported intervals include minimum weighted averages of 3.0 g/t Au diluted over core lengths of at least 2.0 metres. All NQ core assays reported were obtained by either 1-kilogram screen fire assay or standard 50-gram fire-assaying-AA finish or gravimetric finish at (i) ALS Laboratories in Val d'Or, Québec, Thunder Bay, Ontario, Sudbury, Ontario or Vancouver, British Colombia, or (ii) Bureau Veritas in Timmins, Ontario. The 1-kilogram screen assay method is selected by the geologist when samples contain coarse gold or present a higher percentage of pyrite than surrounding intervals. Selected samples are also analyzed for multi-elements, including silver, using an Aqua Regia-ICP-AES method at ALS Laboratories. Drill program design, Quality Assurance/Quality Control ("QA/QC") and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices. Standards and blanks are included with every 20 samples for QA/QC purposes by the Corporation as well as the lab. Approximately 5% of sample pulps are sent to secondary laboratories for check assay.

About the Windfall Lake Gold Deposit
The Windfall Lake gold deposit is located between Val-d'Or and Chibougamau in the Abitibi region of Québec, Canada. The mineral resource defined by Osisko, as disclosed in the Windfall Lake Technical Report (as defined below) and November 27, 2018 Lynx resource update, comprises 2,874,000 tonnes at 8.17 g/t Au (754,000 ounces) in the indicated mineral resource category and 10,352,000 tonnes at 7.11 g/t Au (2,366,000 ounces) in the inferred mineral resource category. For details regarding the key assumptions, parameters and methods used to estimate the mineral resources presented in respect of the Windfall Lake gold project, please see the technical report entitled "Technical Report and Mineral Resource Estimate for the Windfall Lake Project, Windfall Lake and Urban-Barry Properties" and dated June 12, 2018 (effective date of May 14, 2018), which has been prepared by InnovExplo Inc. from Val-d'Or, Québec (the "Windfall Lake Technical Report") and the press release “Osisko Releases Mineral Resource Update for Lynx” dated November 27, 2018, which has been prepared by Osisko and reviewed and approved by Micon International, Ltd. from Toronto, Ontario. The Windfall Lake Technical Report and press release are available on Osisko's website at www.osiskomining.com and on SEDAR under Osisko's issuer profile at www.sedar.com. The Windfall Lake gold deposit is currently one of the highest-grade resource-stage gold projects in Canada. Mineralization occurs in four principal zones: Lynx, Zone 27, Caribou and Underdog. All zones comprise sub-vertical lenses following intrusive porphyry contacts plunging to the northeast. The deposit is well defined from surface to a depth of 900 metres and remains open along strike and at depth. Mineralization has been identified 30 metres from surface in some areas and as deep as 2,000 metres in others, with significant potential to extend mineralization down-plunge and at depth.

About Osisko Mining Inc.
Osisko is a mineral exploration company focused on the acquisition, exploration, and development of precious metal resource properties in Canada. Osisko holds a 100% interest in the high-grade Windfall Lake gold deposit located between Val-d'Or and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding the Urban Barry area and nearby Quévillon area (over 2,700 square kilometres).

Cautionary Note Regarding Forward-Looking Information
This news release contains "forward-looking information" within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. The information in this news release about the Windfall Lake gold deposit being one of the highest grade resource-stage gold projects in Canada; the significance of results from the new infill drilling and ongoing drill definition and expansion program at the Windfall Lake gold project; the significance of assay results presented in this news release; the deposit remaining open along strike and at depth; potential depth extensions of the mineralized zones down-plunge and at depth; the actual mineralization of local visible gold; the current 800,000 metre drill program; the type of drilling included in the drill program; potential mineralization; the potential to extend mineralization up and down-plunge and at depth at the Windfall Lake gold deposit; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities, including the continuity or extension of any mineralization; and any other information herein that is not a historical fact may be "forward-looking information". Any statement that involves discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as "expects", or "does not expect", "is expected", "interpreted", "management's view", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward- looking information. This forward-looking information is based on reasonable assumptions and estimates of management of the Corporation at the time such assumptions and estimates were made, and involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Osisko to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management's geological modelling; the ability of Osisko to complete further exploration activities, including drilling; property interests in the Windfall Lake gold project; the ability of the Corporation to obtain required approvals and complete transactions on terms announced; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions. Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information, Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

For further information please contact: 
John Burzynski
President and Chief Executive Officer 
Telephone: (416) 363-8653