Career
Thomas played rugby union for Barbarian F.C. against South Africa in November 1915. By this time, Gwyn Thomas had played rugby league for Wigan, the animosity between the rugby union, and rugby league code would normally have precluded any rugby league football player from ever playing rugby union again, however this match took place during World War I, and for the morale of the country, the antagonism between the codes was temporarily relaxed. Thomas was selected to go on the 1920 Great Britain Lions tour of Australia and New Zealand.