The Plymouth Reliant was one of the first two so called "K Cars" (the other being the Dodge Aries) the Chrysler Corporation introduced for the 1981 model year. The Reliant replaced the slow selling and poorly assembled Plymouth Volare', which was the short-lived successor automobile to the highly regarded Plymouth Valiant. The models are largely credited for helping Chrysler recover from bankruptcy. They also raised the standard for quality for American automakers in general. They are based on the Chrysler K platform. The Reliant was Motor Trend magazine's Car of the Year for 1981.

Plymouth Reliants were built in Newark, Delaware, Toluca, Mexico and Detroit. The last Plymouth Reliant rolled off the assembly line on December 9, 1988. The 1989 Reliant was a carryover from 1988.