The son of Arthur Oswald Diggins and Lucy Dolphin "Dolly" Diggins, née Mountain, Diggins was born on 26 December 1906. He married Amanda Eileen Murphy in 1928. He died on 14 July 1971.
In 1932, during the Great Depression, Diggins moved to Victoria to play for the South Melbourne Football Club in the VFL. Diggins was one of several Subiaco players who joined South Melbourne in the early 1930s, including Johnny Leonard, Bill Faul and John Bowe, with the promise of immediate, long-term, secure, paid employment outside of football within the grocery empire of the South Melbourne president, South Melbourne Lord Mayor, and Member of the Victorian Legislative Council, Archie Crofts. The influx of players from interstate became known as South Melbourne's "Foreign Legion", and helped South's on-field performance significantly. Diggins won one premiership with South Melbourne in 1933, and played there until 1937.
Carlton
Having been denied the opportunity to coach at South Melbourne, Diggins reluctantly moved to the Carlton Football Club in 1938, and was appointed captain-coach — he had been denied a transfer to Carlton a year earlier. He flourished at Carlton. In his first season, he led the team to the 1938 premiership. He played two more seasons with Carlton, He played his last senior game in round four against Melbourne, when he suffered a serious injury to a knuckle. Due to that injury, and number of illnesses, he did not play for Carlton again that year, on medical advice; however he did continue as non-playing coach until the end of the 1940 season.
Military service
Having earlier intimated an inclination to enlist in the R.A.A.F., once Carlton's 1940 VFL season had finished, Diggins enlisted in the Second AIF. He re-enlisted in 1942; and, as Staff Sergeant Diggins, he took an active part in the training of commandos at the Army Physical and Recreational Training School in Frankston.
Frankston
In 1947, he was appointed non-playing coach of Frankston Football Club. In September 1947, when an injured player was unable to return to the field after half-time, he "took the field received a great ovation from the Frankston supporters. Diggins is the biggest man seen in Peninsular football for a long time. "Football News" put his weight down at 17 stone ". and, in the following season, aged 41, he made another comeback, in which "he played inspiring football and was largely responsible for his side's two-goal win". He coached Frankston for three seasons.
The Argus
In 1950, he became a football reporter for The Argus.
