The Mitsubishi 4A9 engine is the newest family range of all-alloy inline four-cylinder engines from Mitsubishi Motors, introduced in the 2004 version of their Mitsubishi Colt supermini, and built by DaimlerChrysler-owned MDC Power in Germany.

The Mitsubishi Colt is a nameplate from Mitsubishi Motors that has been applied to a number of automobiles since 1962. It was first introduced with a series of kei and subcompact cars in the 1960s, and then for the export version of the subcompact Mirage between 1978 and 2002. Chrysler, Mitsubishi's longtime partner, also used the name when applying its long-running practice of rebadging Mitsubishi vehicles as the Dodge and Plymouth Colt captive imports for the North American market between 1970 and 1994.