1998–99 Idaho Vandals men's basketball team

The 1998–99 Idaho Vandals men's basketball team represented the University of Idaho during the 1998–99 NCAA Division I men's basketball season. Members of the Big West Conference, the Vandals were led by second-year head coach David Farrar and played their home games on campus at the Kibbie Dome in Moscow, Idaho.

The Vandals were 16–10 overall in the regular season and 11–5 in conference play, third in the East division standings. In the regular season finale, Idaho defeated rival Boise State before 7,323 at the Kibbie Dome, the largest home attendance in a decade.

They met Long Beach State in the first round of the conference tournament and lost by five points.

Postseason result
!colspan=6 style=| Big West tournament