Roy Lee Richards, 42, was heading south on FM 1226, five miles north of Hawley, just after 7 p.m. when his vehicle veered off the road to the west, Department of Public Safety officials said.
Richards then overcorrected, and the Geo Tracker flipped.
Richards was not injured, but his passenger, 49-year-old Richard Luera of Stamford, was killed in the crash.
Luera was not wearing a seat belt, according to DPS officials.
DPS officials are continuing their investigation.