The 2009 GP2 Series season was the forty-third season of the second-tier of Formula One feeder championship and also fifth season under the GP2 Series moniker. The season consisted of twenty races at ten rounds, beginning on 9 May at the Circuit de Catalunya and finishing on 20 September at the Autódromo Internacional do Algarve. The Algarve circuit hosted its first GP2 weekend, and was the only new circuit on the calendar. The Nürburgring also returned as part of its rotation with Hockenheim as the home of the German Grand Prix.
The title was won by German rookie Nico Hülkenberg at the penultimate round of the championship at Monza, the first time the series had been won before the final round. His team ART Grand Prix claimed the teams title in the Algarve.
Barwa Addax's title contender Romain Grosjean left the series mid-season to join the Renault for the remainder of the Formula One season following Nelson Piquet Jr.'s sacking.
Champion Hülkenberg, runner-up Petrov and 3rd place Lucas di Grassi all drove in the 2010 Formula One season for Williams, Renault and new team Virgin Racing respectively. 16th place Kamui Kobayashi took part in the final two races of the 2009 Formula One season for Toyota following Timo Glock's injury in the Japanese Grand Prix while 18th place Karun Chandhok joined new Formula One team HRT in 2010.