Born in Glasgow, inside left Johnny Deakin played for St Johnstone Juniors from where he was signed by Scottish League club St Mirren in May 1937, establishing himself in their first team before the outbreak of the Second World War in September 1939.
During the Second World War he served in the Army, playing once for Partick Thistle in a Glasgow Cup defeat to Rangers in September 1940, and while serving in Ireland he played for Glentoran. He also played as a guest for Aberdeen in 1943 and for Brentford in 1944, and won The Summer Cup with St Mirren in 1943 as they beat Rangers. After demobilisation he returned to St Mirren and won a single cap for Scotland when he played in a 2-2 draw with Belgium at Hampden Park in January 1946, as well as wartime caps against England and Wales.
Possessing “grand all round ability”, he scored 46 goals in 280 appearances for St Mirren, and played 3 matches for The Scottish League between April 1948 and October 1949 against The League of Ireland and The Irish League, against whom he scored a hat-trick at Ibrox Park in September 1949, before joining Clyde for £7,000 in November 1949, where he scored 8 goals in 17 appearances before returning to Irish football in 1951. He first played for Linfield in 1951-52, scoring twice in 10 matches, and had a spell at Bangor in 1952 where he scored 3 times in 12 appearances. He then joined Glentoran, where he played for three seasons, scoring 6 goals in 26 appearances before his retirement in 1955.