Originally from Tasmania where he had been a premiership player with North Hobart Football Club, Mason debuted for St Kilda in the 1922 VFL season. He was a wingman but towards the end of his career was used as a ruckman. In 1926 Mason tied with Harold Matthews for St Kilda's Best Player award[2] and represented Victoria at interstate football for the first of six times.
After leaving St Kilda Mason played with Camberwell Football Club in the Victorian Football Association (VFA), which had just finished in last place in the VFA, as captain-coach. His arrival sparked the emergence of the Tricolours as a VFA force for the first time, but a runner-up spot to Yarraville in 1935 was the closest they could get to a flag. Mason was playing coach of Camberwell 1932 and 1933.