The Dodge Omni is a subcompact car that was manufactured by Chrysler Corporation from the 1978 to 1990 model years. Marketed alongside the Plymouth Horizon, the Omni was the first front-wheel drive Chrysler vehicle; the pair were the first front-wheel-drive economy cars assembled in the United States.

The Omni and Horizon were developed from the Chrysler Horizon designed by Chrysler Europe, undergoing extensive modifications to meet U.S. standards. The design was heavily inspired by the Volkswagen Rabbit five-door hatchback (with early versions using Volkswagen-produced engines). Known as the Chrysler L platform, the chassis architecture used by the Omni/Horizon was also adopted by 3-door coupes and 2-door coupe-utility pickups.

Through its twelve-year production, approximately 2.5 million units of the combined model lines were sold, with the Plymouth Horizon outselling the Dodge Omni (the final Plymouth model to outsell its Dodge counterpart). For 1987, the Dodge Shadow and Plymouth Sundance hatchback sedans were introduced as a successor model line, eventually replacing the Omni/Horizon.

Chrysler produced the model line at its Belvidere Assembly Plant (Belvidere, Illinois) from 1977-1987, with production shifting to the AMC Kenosha Plant (Kenosha, Wisconsin), and ultimately the Jefferson Avenue Assembly (Detroit, Michigan); the Omni/Horizon were the final model lines produced at the latter two facilities.

In the early 1970s, Chrysler Corporation had repeatedly announced it would enter the North American small car market to compete with Chevrolet Vega, Ford Pinto and AMC Gremlin, by developing and manufacturing its own domestic small car, known as its Project R-429 — only to repeatedly delay the project.

In an attempt to stave off the U.S. small car competition, the company increased their stake to 77% of Simca in 1963 and had taken control of the Rootes Group by mid-1964, marketing numerous Simca and Rootes models, e.g. the Simca 1204 and Sunbeam Arrow via a new Simca-Rootes Division, formed in 1966 — with 850 dealers selling four Simca models and 400 dealers selling four Rootes models. Results were dismal, and in late 1969, Chrysler announced it would market its Rootes and Simca products directly via its Chrysler-Plymouth Division.

Chrysler introduced its newly developed Hillman Avenger to the U.S. and Canadian market for model years 1971-1973 as the rebadged Plymouth Cricket, directly via its Plymouth dealerships — as a 4-door saloon/sedan (and a 5-door station wagon for MY 1972). The Cricket, and the Mitsubishi-built Colt, marketed concurrently by Dodge dealerships, were both seen in the industry as stop-gap measures until Chrysler could design a small car to be domestically manufactured. The Cricket in particular failed to resonate in the market.

At the same time Chrysler marketed these captive imports, Chrysler executives denounced the concept of subcompact cars, Chrysler's Chairman, Lynn A. Townsend saying "the subcompacts are just too small, the American people won't climb into them. They have to give up too much in creature comfort.