[2] Chelsea could not defend their title as they automatically qualified for the 2013–14 UEFA Champions League and also reached the knockout stage.

However, this additional entry was not necessary for this season, because the title holders qualified for European competitions through their domestic performance.

[6][7] Apart from the allocation based on the country coefficients, associations may have additional teams participating in the Europa League, as noted below:

They were: Hapoel Ramat Gan (2nd tier), Hødd (2nd), Pasching (3rd), Teteks (2nd), Vaduz (2nd) and Wigan Athletic (2nd).

[9] Matches in the qualifying, play-off, and knockout rounds may also be played on Tuesdays or Wednesdays instead of the regular Thursdays due to scheduling conflicts.

Inter Turku lodged a protest after losing the second leg to Víkingur Gøta,[41][42] and two match officials were later banned for life by UEFA for attempted match-fixing.

[31][32][33] UEFA decided to replace Beşiktaş in the Europa League group stage with Tromsø, who were eliminated by Beşiktaş in the play-off round,[34] while a draw was held to select a team to replace Fenerbahçe among the teams eliminated in the play-off round,[35] and was won by APOEL.

Swansea City, Kuban Krasnodar, Sankt Gallen, Ludogorets, Chornomorets Odesa, Esbjerg, Elfsborg, Zulte Waregem, Wigan Athletic, Paços de Ferreira, Pandurii Târgu Jiu, Eintracht Frankfurt, APOEL, Thun, Slovan Liberec, SC Freiburg, Estoril, Real Betis, Vitória de Guimarães, Rijeka, Trabzonspor, Apollon Limassol, Tromsø and Shakhter Karagandy all made their debut in UEFA Europa League group stage (although Elfsborg, Zulte Waregem, Eintracht Frankfurt, Slovan Liberec, Vitória de Guimarães and Tromsø played already in UEFA Cup as well as Thun, Real Betis, Trabzonspor already disputed the UEFA Cup/UEFA Europa League knockout stage).

In the knockout phase, teams played against each other over two legs on a home-and-away basis, except for the one-match final.