The 1986 1. divisjon was the 42nd completed season of top division football in Norway. The season began on 27 April 1986 and ended on 19 October 1986. 22 games were played with 2 points given for wins and 1 for draws. Number eleven and twelve were relegated. The winners of the two groups of the 2. divisjon were promoted, as well as the winner of a series of play-off matches between the two second-placed teams in the two groups of the 2. divisjon and number ten in the 1. divisjon.