The 2009 1. divisjon (referred to as Adeccoligaen for sponsorship reasons) was a Norwegian second-tier football season.
The season began play on 5 April 2009 and will end on 1 November 2009.
Sandnes Ulf and Hødd were relegated to the 2. divisjon in 2008 after finishing in fifteenth and sixteenth place respectively.
Tromsdalen, Stavanger, Mjøndalen, and Skeid were promoted from the 2. divisjon in 2008.
The two winning sides from the first round, Sarpsborg 08 and Kongsvinger, took part in a two-legged play-off to decide who would play in the 2010 Tippeligaen.