The 2018–19 Southern Utah Thunderbirds basketball team represented Southern Utah University during the 2018–19 NCAA Division I men's basketball season.

The Thunderbirds were led by third-year head coach Todd Simon and played their home games at the America First Events Center in Cedar City, Utah as members of the Big Sky Conference.

They defeated Idaho State and Northern Colorado to advance to the semifinals of the Big Sky tournament where they lost to Eastern Washington.

They were invited to the CollegeInsider.com Tournament where they defeated Drake in the first round before losing in the second round to Cal State Bakersfield.

In the Big Sky tournament they defeated Idaho State and Idaho to advance to the semifinals where they lost to Eastern Washington.