O3 Mining Intersects 1.2 g/t Au Over 28.2 m and 2.2 g/t Au Over 5.1 m Near Surface From Simkar Sector at Alpha Property

New drilling results from six holes drilled in the Simkar sector in late 2020 include:

Drilling Highlights from hole O3AL-20-326

• 1.2 g/t Au over 28.2 metres
• • incl. 2.0 g/t Au over 5.1 metres
  • incl. 8.0 g/t Au over 0.5 metres
  • incl. 4.4 g/t Au over 2.7 metres
• 2.2 g/t Au over 5.1 metres
• • incl. 17.8 g/t Au over 0.5 metres

A 3D-model of the Alpha property is available on the Company's website at https://o3mining.com/presentations/drill-results.

The Simkar sector comprises several East-West trending iron-rich gabbros and basalts covering an area of 5 kilometres by 2 kilometres. The main dyke hosts the former Simkar mine. The drill holes reported today aimed to test the extensions of multiple zones known from historical surface exploration work and shallow drill holes extending over an area of roughly 1.2 square kilometres, located approximately 700 metres south of the historical Simkar mine. O3 Mining's 2020 trenching program helped improve the geological understanding of the controls of these zones in preparation for drilling this winter. The encouraging results received from this initial drilling program support a decision to continue drilling to further explore for mineralized extensions of the VD-L17 zone, which remains partially open laterally and fully open at depth.

"Drilling at Simkar is successfully intercepting gold mineralization at relatively shallow depths and advancing the possibility of developing another potential ore body with good grade and width. The success of these holes further validates the multi-exploration technique approach we are taking to developing drill targets, which bodes well for future success of finding extensions to these zones as our drilling program continues," said President and CEO Jose Vizquerra.

O3 Mining's 2020-2021 drilling program includes 100,000 metres for the Alpha property, which hosts multiple mineralized systems over an approximate 20 kilometres strike length. The program is focused on expanding known deposits at depth at the Bulldog-Orenada, Simkar, and Akasaba sectors, as well as follow-up on the significant previous drill, intercepts to prove the continuity of grades and widths to define new deposits and to make new discoveries in the vicinity of those deposits or in the Omega sector. These targets were generated in 2020 from a combination of in-house geological compilation data, a summer trenching program, and the use of Artificial intelligence ("AI") targeting study by Mira Geoscience (See Press Release December 02^nd, 2020).

Table 1 includes additional intercepts of interest from the VD zones. A further interpretation is required to understand their significance and decide on potential follow-up drilling. A total of seven drill holes totalling 3,282 metres have been drilled in 2020 in this part of the Simkar sector. Assay results from three drill holes are pending. Now that winter conditions allow access to wetlands the drilling focus has shifted to other areas of the Alpha property. Follow-up drilling on the intercepts reported here will occur during the summer months.

Table 1: Drill Hole Intercepts from Simkar sector (only intercepts above 5 g/t Au * m are reported)

Table 2: Drill Hole Details

Hole O3AL-20-326 intersected VD-L17 at approximately 150 metres below channels O3AL-D20-01-015 that returned 9.0 g/t Au over 1.3 metres and O3AL-D20-01-008 cut 7.8 g/t Au over 0.7 metres (See Press Release August 27^th, 2020). Historical shallow drill holes 50 metres underneath the trench returned 1.5 g/t Au over 13.7 metres and 3.4 g/t Au over 4.6 metres. The intercept in hole O3AL-20-326 expanded the VD-L17 zone a further 100 metres vertically. The zone corresponds to a shear zone affecting an iron-rich gabbroic dyke and the surrounding mafic volcanic rocks. The first interval extends from the upper contact to the middle of the dyke and yielded 1.2 g/t Au over 28.2 metres, including three higher-grade intervals. The upper-contact returned 2.0 g/t Au and 4.2 g/t Ag over 5.1 metres where the mafic brecciated volcanic rocks are strongly sheared. Mineralization consists of up to 2% sphalerite stringers, contrary to the gabbro where mineralization consists of the percolation of pyrrhotite and chalcopyrite. The gabbro is further cross-cut by a tourmaline-rich fault-fill vein yielding 8.0 g/t Au and 4.8 g/t Ag over 0.5 metres. Mineralization near the middle of the gabbro consists of fracture filling pyrrhotite, chalcopyrite, and calcite, yielding 4.4 g/t Au over 2.7 metres. The lower contact with the mafic volcanic rocks returned an interval of 2.2 g/t Au over 5.1 metres. This contact is also strongly sheared and contains up to 5% quartz veinlets locally containing visible gold and returning 17.8 g/t Au over 0.5 m.

Hole O3AL-20-324 returned 7.2 g/t Au over 1.0 metres located 300 metres west of O3AL-20-326 at 200 metres vertical depth. Even though low grade, this intercept confirms the continuity of the VD-L17 zone.

Figure 1: Alpha Property Map

Figure 2: Simkar Sector Drilling Map

Qualified Person

The scientific and technical content of this news release has been reviewed, prepared, and approved by Mr. Louis Gariepy. (OIQ #107538), VP Exploration, 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 currently unknown but is estimated at 65-80% of the reported core length interval for the zones. 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. Half-core samples are shipped to Agat laboratory in Val-d'Or, Québec and Mississauga, Ontario for assaying. The core is crushed to 75% passing -2 mm (10 mesh), a 250 g split of this material is pulverized to 85% passing 75 microns (200 mesh) and 50 g is analyzed by Fire Assay (FA) with an Atomic Absorption Spectrometry (AAS) finish. Samples assaying >10.0 g/t Au are re-analyzed with a gravimetric finish using a 50 g charge. Commercial certified standard material and blanks are systematically inserted by O3 Mining's geologists into the sample chain after every 18 core samples as part of the QA/QC program. Third-party assays are submitted to other designated laboratories for 5% of all samples. Drill program design, Quality Assurance/Quality Control ("QA/QC") and interpretation of results are performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices.

About O3 Mining Inc.

O3 Mining Inc., an Osisko Group company, is a gold explorer and mine developer ready to produce from its highly prospective gold camps in Québec, Canada. O3 Mining benefits from the support, previous mine-building success, and expertise of the Osisko team as it grows towards being a gold producer with several multi-million ounce deposits in Québec.

O3 Mining is well-capitalized and owns a 100% interest in all its properties (137,000 hectares) in Québec. O3 Mining trades on the TSX Venture Exchange (TSX.V: OIII) and OTC Markets (OTCQX: OIIIF). The company is focused on delivering superior returns to its shareholders and long-term benefits to its stakeholders. Further information can be found on our website at https://o3mining.com/

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 transaction; 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 it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the companies 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 restart of operations; further steps that might be taken to mitigate the spread of COVID-19; the impact of COVID-19 related disruptions in relation to the Corporation's business operations including upon its employees, suppliers, facilities and other stakeholders; uncertainties and risk that have arisen and may arise in relation to travel, and other financial market and social impacts from COVID-19 and responses to COVID 19. 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, the parties cannot assure shareholders and prospective purchasers of securities 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 the Corporation nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. The Corporation 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.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

SOURCE O3 Mining Inc.



Contact
on O3 Mining, please contact: José Vizquerra Benavides, President, CEO and Director, Toll-Free: +1 (833) 979-3516, Telephone: +1 (873) 381-2014, info@o3mining.com; 1440-155 University Avenue, Toronto, ON M5H 3B7