The 2019 Ontario Men's Curling Championship, better known as the Tankard, the 2019 provincial men's curling championship for Southern Ontario, was held from January 27 to February 3 at the Woolwich Memorial Centre in Elmira, Ontario. The winning Scott McDonald team would represent Ontario at the 2019 Tim Hortons Brier in Brandon, Manitoba. The event is being held in conjunction with the 2019 Ontario Scotties Tournament of Hearts, the provincial women's curling championship.

Unlike the 2018 event, the 2019 Tankard returned to having a round-robin format.

The original qualification process called for 10 teams to qualify from three cash spiels (two each), an open qualifier (two teams), plus the top two southern Ontario teams in the CTRS standings (as of December 9, 2018).^[2] However, CurlON announced on December 5, 2018 that a third CTRS team (Team Scott McDonald) would be allowed to directly qualify for the Tankard, as the team was in the top 10 in the CTRS standings at the time, and had a scheduling conflict preventing them from participating in the first round of cash spiel qualifiers (they were playing in the 2018 National). McDonald's direct entry took a qualifying spot away from Cash Spiel #2.^[3] This change in qualification was not without controversy.^[4]

The team lineups are as follows:^[5]