Plymouth United Football Club was a football club from Plymouth, Devon, England, formed at least by 1877. It was reported that they were beaten 6–0 at home by Torquay & South Devon Football Club on 22 December that year, and that the Torquay team were surprised by the poor standard of their opposition.
As a pioneering club in Devon it played against Argyle Football Club in its first season and was one of eight founding members of the Devon County Football Association.
Another team called Plymouth United was formed in 1944, along with Plymouth City, made up of ex-Plymouth Argyle and local amateurs. They played against local sides and service teams helping to re-establish football in the area. A team of the same name entered the FA Cup in 1946, 1947 and 1950, failing to win a match.