The Plymouth GTX was a muscle car produced by the Plymouth division of the Chrysler Corporation from 1967 to 1971. Marketed as the "gentleman's muscle car" and positioned as an upscale derivative of the Belvedere, in 1968 the GTX branding was moved to the Road Runner instead. For 1971 the GTX was redesigned to have a more fuselage-styled body. The convertible was dropped from the lineup, leaving the hardtop as the only body style. Due partly to rising insurance rates on muscle cars, sales were low. After 1972, the GTX was assimilated back into the Road Runner lineup but retained the branding of both cars. 2,942 were produced.
The casting was retooled in 2021, with the side trim pieces becoming a separate piece to the base.