The 2019–20 Big 12 men's basketball season began with practices in October 2019, followed by the start of the 2019–20 NCAA Division I men's basketball season in November.

Regular season conference play started in December 2019 and concluded in March 2019.

The Big 12 tournament was scheduled to be held from March 11 through 14 and will be played at the Sprint Center in Kansas City, Missouri, but it was cancelled after the first round due to the coronavirus pandemic.

[1] There were no head coaching changes following the 2018–19 Big 12 Conference men's basketball season.

Teams will be seeded by record within the conference, with a tiebreaker system to seed teams with identical conference records.