The 2006 season of the 3. divisjon, the fourth-highest association football league for men in Norway.
Between 20 and 22 games (depending on group size) were played in 24 groups, with 3 points given for wins and 1 for draws. Twelve teams were promoted to the 2. divisjon through playoff.
There was a redesigning of the 3. divisjon to better fit geographical boundaries next season. Fewer teams than usual were relegated; purposely none from the Oslo district and none from Agder.