The 2018–19 Stephen F. Austin Lumberjacks basketball team represented Stephen F. Austin State University during the 2018–19 NCAA Division I men's basketball season. The Lumberjacks were led by third-year head coach Kyle Keller and played their home games at the William R. Johnson Coliseum in Nacogdoches, Texas as members of the Southland Conference. They finished the season 14–16 overall, 7–11 in Southland play to finish in a tie for ninth place. Since only the top eight teams are eligible to play in the Southland tournament, the Lumberjacks failed to qualify this season.