Okayama International Circuit, Motorsport racing track in Mimasaka, Japan

Okayama International Circuit is a motorsport racing track in Mimasaka, Japan, that winds through 3.7 km (2.3 miles) of hilly terrain. The facility combines fast straights with tight hairpin turns and several elevation changes that offer technical challenges for drivers and motorcycle riders.

Built by Tanaka International, a golf-course developer headed by Hajime Tanaka, the track opened on 18 November 1990 as TI Circuit Aida, a members-only club whose 15 million yen joining fee included drives in a 1987 Tyrrell F1 car. It hosted the Formula One Pacific Grand Prix in 1994 and 1995, both won by Michael Schumacher. After parent company Tanaka International filed for civil rehabilitation in March 2003, Unimat Holding took over; the operating company became Okayama International Circuit Co., Ltd. in May 2004 and the circuit took its present name on 1 January 2005. Aska Corporation bought it in March 2012.

The circuit's seven corners carry the names of British drivers, among them Jonathan Williams, Stirling Moss, Richard Attwood, David Piper, Brian Redman, David Hobbs and Michael Knight. Redman and Hobbs together form the W Hairpin. Since 2019 the official ambassador unit PaRet has recorded the 30th-anniversary song "Road to Victory" and starred in the short anime "Hairpin Double", broadcast on BS Fuji on 4 February 2022.

The venue sits around 20 km (12 miles) south of Tsuyama and can be reached by road from larger cities in the region. On event days shuttle buses run from the nearest train station because parking spaces on site are limited.

The 2020 works added a motorcycle chicane outside Williams Corner and widened the Moss S escape zone; the lap length stayed 3,703 m. The outright unofficial record, 1:10.218, was set by Ayrton Senna in a Williams FW16 during qualifying for the 1994 Pacific Grand Prix.