The Lancia Delta Group A is a Group A rally car built for the Martini Lancia by Lancia to compete in the World Rally Championship. It is based upon the Lancia Delta road car and replaced the Lancia Delta S4.

The car was introduced for the 1987 World Rally Championship season and dominated the World Rally Championship, scoring 46 WRC victories overall and winning the constructors' championship a record six times in a row from 1987 to 1992, in addition to drivers' championship titles for Juha Kankkunen (1987 and 1991) and Miki Biasion (1988 and 1989). During the early 1980s the top level of rallying was dominated by the Group B formula, for which Lancia produced the rear-drive 037 and then, when that became obsolete, the Delta S4.

The entire formula was abolished at the end of the 1986 season, however, after a string of fatal accidents, leaving Group A as the top formula for the 1987 and subsequent seasons.