The 1986 New Zealand National Soccer League was the 17th season of a nationwide round-robin club competition in New Zealand football. Mount Wellington finished as champions, one point ahead of Miramar Rangers.
Napier City Rovers finished last in the 1985 league, and took part in a play-off with the winners of the northern, central, and southern leagues (Takapuna City, Manawatu United, and Rangers respectively). Palmerston North-based Manawatu United were promoted to the league, their first appearance in the top flight since 1979
There was to be no relegation at the end of the 1986 season, as it was decided to increase the size of the league to 14 teams. Auckland University were ejected from the league at the end of the season for failing to meet NZFA criteria, and three teams were promoted from the regional leagues.
One other new team appeared in the league, Wellington United. They were formed by an amalgamation of 1985 champions Wellington Diamond United and Central league side Wellington City, who had been one of the national league's inaugural members under the name Hungaria.
The 1986 season was not a vintage one for brilliant play, but did produce its share of entertainment, especially from Miramar Rangers, Papatoetoe, and new composite side Wellington United, who were formed from 1986 champions Wellington Diamond United and former league side Wellington City. the league devolved into two groups with a large gap separating the top five from the bottom seven sides.