The 2009–10 UEFA Europa League group stage matches took place between 17 September and 17 December 2009.
The group stage featured the 38 winners of the play-off round and the 10 losing sides of the Champions League play-off round.
Following the completion of the group stage, the top two teams in each group advanced to play in the round of 32, where they will be joined by the eight third-placed teams from the Champions League group stage.
The draw for the group stage was held in Monaco on 28 August 2009.
Seeding was determined by the UEFA coefficients: Pot 1 held teams ranked 9–32, Pot 2 held teams ranked 35–74, Pot 3 held teams ranked 76–108, while Pot 4 held teams ranked 115–203 and unranked teams.
Clubs from the same association were paired up to split the matchdays between Thursday.
th Title Holder
CL Losing teams from the Champions League play-off round
Based on Article 7.05 in the UEFA regulations, if two or more teams are equal on points on completion of the group matches, the following criteria will be applied to determine the rankings: