Rotherham United F.C. are a football club in the English Football League. They were formed in Rotherham, England, in 1889.

A club was founded as Rotherham in 1870, and changed their name to Rotherham Town. Meanwhile, a team named Thornhill formed in 1877, before renaming themselves Rotherham County, and being admitted to the league in 1919. The two teams merged in 1925 to form the present club.

Rotherham play at the Millmoor ground, and as a result are nicknamed the "Millers" (or occasionally the "Merry Millers"). Their home strip is red with white shorts. They currently play in the English First Division, the highest level they have ever played at.

In 1961, Rotherham lost the League Cup final to Aston Villa F.C, while in 1996, they won the Auto Windscreens Shield.