The 2009–10 Austrian Football First League (German: Erste Liga, also known as ADEG Erste Liga due to sponsorship) was the 36th season of the Austrian second-level football league. It began on 14 July 2009 and ended on 28 May 2010.
The season is the last one played with twelve teams, as league size will be reduced to ten for 2010–11. The reserve teams of Austrian Bundesliga clubs Red Bull Salzburg and Austria Vienna will be demoted to the Regionalliga after the season regardless of their final position. The last-placed of the remaining ten teams will also be relegated, while the team ranked ninth will compete with the Regionalliga champions for another spot in the 2010–11 season.
SV Grödig, DSV Leoben and 1. FC Vöcklabruck finished the 2008–09 season in the bottom three places and were relegated to their appropriate Regionalliga division. The three relegated teams were replaced by Regionalliga division champions First Vienna (East), TSV Hartberg (Central) and FC Dornbirn 1913 (West).
Source: bundesliga.at Rules for classification: 1) points; 2) goal difference; 3) number of goals scored. (C) Champions; (P) Promoted; (R) Relegated Notes:
^ abRed Bull Salzburg Reserves and Austria Vienna Reserves will be relegated to the Regionalliga at the end of the season regardless of their final position.
^Since Austria Kärnten did not obtain First League license and were therefore relegated from Bundesliga to Regionalliga, promotion/relegation play-offs between First Vienna and SV Grödig were cancelled with both teams obtaining a spot in the 2010–11 Austrian Football First League.