The Muntz Jet is a very rare American sports car. 198 of these cars were built between 1950 and 1954. It was designed by Earl "Madman" Muntz, a used-car magnate / inventor. Earl Muntz was also the inventor of the 4-track tape player, and an early maker of black-and-white television sets.

In 1950, Madman Muntz bought Frank Kurtis's car company, which specialized in race cars. The prototype was a Cadillac-engined Lincoln that Frank Kurtis had built several years earlier. The original Muntz Jets were very similar to the Kurtis car. They were two-seaters, and were fast and sure-footed cars.

Some legal trouble with Cadillac led to the second incarnation of the Muntz Jet, which was the first four-seated sports car ever built. The Muntz Jet now used a Lincoln engine, and various other Ford and Lincoln parts. It was rumored that the Ford Thunderbird was based, at least partially, on the Muntz Jet.

While the Muntz Jet was a successful design, it was an unsuccessful financial proposition. Economy of scale was a problem, as many Muntz Jets were custom-built. Some had telephones. Others had liquor cabinets and bars. Madman Muntz claimed to have lost nearly half a million dollars on the car, when production was discontinued in 1954.

As many as 50 of the original 198 Muntz Jets survive to the present day.