Thornliebank, Renfrewshire born inside left Bill Finlayson began his football career with Glasgow Ashfield in 1918 and played for Thornliebank in 1919 before joining First Division Chelsea in 1920, making his Football League debut at Bolton Wanderers in January 1922. However he was very much a fringe player at Stamford Bridge, and made four further appearances between October and November 1923, scoring in a 1-1 draw at Cardiff City, but was unable to get into Chelsea’s team on a regular basis despite their slide towards relegation at the season end.
He joined Second Division Clapton Orient in the 1924 close season where he scored twice in 22 appearances for The O’s in a single season at Lea Bridge Road, before signing for Third Division (South) Brentford in the summer of 1925, scoring 5 goals in 22 appearances during their 1925-26 campaign.
Finlayson then joined the exodus to the nascent American Soccer League, initially with Springfield Babes where he scored once in 16 matches in 1926-27. Before the end of the season he had joined Providence Clamdiggers, where he scored 9 goals in 115 appearances over the next two seasons, also playing 5 matches on loan for Montreal CNR in the Canadian National Soccer League during two spells in 1928 and 1929. He joined Bethlehem Steel in 1930 where he played in 22 matches before returning to Canada to rejoin Montreal CNR, making 3 further appearances for them before his retirement.