Thomas, who was born in Broken Hill, started out in the Goldfields Football League where he played for the Warriors.
He was a member of six premierships, five of them in succession, and won a Sandover Medal in 1923 to become the first ever East Perth player to win the award.
He represented Western Australia in a total of twelve interstate matches, including the 1914, 1921 and 1924 carnivals.
At the Sydney Carnival of 1914 he put in a memorable performance in a game against Queensland, kicking 14 goals.
Thomas retired at the end of the 1928 season, having also spent some time coaching in New South Wales, with his 247 career games remaining a West Australian elite football record until it was broken by Ray Schofield in Round 10 of 1958; Schofield retired at the end of that season having played 259 games.