The 2009 1000 km of Okayama was the inaugural event of Automobile Club de l'Ouest's (ACO) Asian Le Mans Series. It was held at the Okayama International Circuit, Japan and feature two 500 km races held on 30 October and 1 November 2009. The winning teams in each of the four categories earned an automatic invitation to the 2010 24 Hours of Le Mans. A second Asian Le Mans Series event, scheduled for the Shanghai International Circuit, China, on 7 and 8 November was cancelled by the ACO due to economic circumstances. The race weekend is being shared with the World Touring Car Championship's Race of Japan.

The Asian Le Mans Series (AsLMS) is an Asian sports car racing endurance series created by the Automobile Club de l'Ouest (ACO) and based in Asia. It is the successor to the defunct Japan Le Mans Challenge which folded in 2007 after its second season. The ACO aims to attract teams and drivers from Asian countries.