Ridge Racer, released in Japan as Ridge Racers, is a 2004 racing video game developed and published by Namco for the PlayStation Portable. An installment in the Ridge Racer series, it was released as a global launch title for the system, on 12 December 2004 in Japan and overseas in 2005. Ridge Racer has been described as a 'compilation' of the series, featuring tracks, cars and remixed soundtrack from previous titles of the 1990s. Gameplay-wise, it marked the change from the "classic" style last seen in Ridge Racer V to the new drifting mechanic and nitrous boost that the series would incorporate from there on, including on Ridge Racer 6 and Ridge Racer 7.

Ridge Racer was critically acclaimed, praised for its visuals, gameplay and soundtrack; it was notable at the time for providing home console-like graphics at a smooth 60 fps framerate on a mobile gaming system, harnessing the PSP's graphical abilities. An updated version with more tracks and modes was released for the PSP in 2006 titled Ridge Racer 2; seven years after Ridge Racer on PSP came Ridge Racer on PlayStation Vita.