The club was founded by Albert Clement, who had played rugby in the town in the 1940s, and Ray Morgan, who became secretary.

The first club to play against the newly formed Trinant RFC was Hafodorynys.

Team colours were decided and the club chose black with white hoops.

This resulted in a bitter complaint from the secretary of Oakdale when eight of their players switched clubs.

The Trinant badge consists of a shield split into quarters.