The 2017–18 Northern Arizona Lumberjacks men's basketball team represented Northern Arizona University during the 2017–18 NCAA Division I men's basketball season. The Lumberjacks were led by sixth-year head coach Jack Murphy and played their home games at the Walkup Skydome in Flagstaff, Arizona as members of the Big Sky Conference. They finished the season 5–27, 2–16 in Big Sky play to finish in last place. They lost in the first round of the Big Sky tournament to Northern Colorado.