Oyonnax Rugby is a French professional rugby union club based in Oyonnax and competing in the Top 14. Founded in 1949 and located in the Ain montainous department, the club plays its home matches at the 11,400-capacity Stade Charles-Mathon, the highest stadium in the league at 532 metres (1,745 ft) and wears black and red jerseys.

Oyonnax is the second most populated commune in the Ain department in the Auvergne-Rhône-Alpes region in eastern France.