Thomas was born in Hobart. He won a silver medal in the Men's Pentathlon A4A9 event at the 1988 Seoul Paralympics. He competed without winning any medals at the 1992 Barcelona Paralympics. At the 1996 Atlanta Games, He won a gold medal in the Men's 4x100 m Relay T42–46, for which he received a Medal of the Order of Australia, and two bronze medals in the Men's 100 m T43–44 and Men's Long Jump F44 event.