The Dutch Eerste Divisie in the 1985–86 season was contested by 19 teams, one more than in the previous season. This was due to FC Emmen entering from the amateurs. FC Den Haag won the championship without losing a single match.
Entered from amateur football
Relegated from the 1984–85 Eredivisie
In the promotion competition, four period winners (the best teams during each of the four quarters of the regular competition) played for promotion to the eredivisie.