Rugby union in Cornwall is Cornwall's most popular spectator sport with a large following. The followers of the national side are dubbed Trelawny's Army. In 1991 and 1999 Cornwall won the County Championship final played at Twickenham Stadium, beating Yorkshire and Gloucestershire respectively to win the Cup. They had another strong spell in the 2010s, reaching seven of the eight finals contested between 2013 and 2022, winning four of them.

Falmouth Rugby Football Club is a rugby union club based in the town of Falmouth, Cornwall, in the United Kingdom, playing in Counties 1 Western West at the seventh tier of the English league system, following promotion from the Tribute Cornwall/Devon league at the end of the 2016–17 season. The club play at the Recreation Ground. They enjoy a rivalry with close neighbours, Penryn.