Trethomas Bluebirds AFC was formed in 1903 as Trethomas Football Club. The pitch was bought by the miners who worked at the mine and coke works of Bedwas & Trethomas. The name Bluebirds came from one of the founders who was a Cardiff City supporter.
The club entered the Gwent County League in 2003, winning promotion to Division Two as Champions in 2005–06. Promotion to Division One followed after the club finished as runners-up in the 2012–13 season. They were promoted to the Welsh Football League in 2015–16 for the first time.
The club is based in the village Trethomas in the Caerphilly County Borough and currently plays in the Ardal Leagues South East, the third tier of the Welsh football pyramid.