The son of Brisbane-based entrepreneur and owner of the Cremorne Theatre, John N. McCallum, John McCallum carved out a distinguished career in the theatre in both Australia and England during the 1940s and 1950s, and later became a successful film and television producer. The middle child in a family of three boys, McCallum and his older brother received their primary school education in England. When the Great Depression forced the family to return to Australia, he entered the Church of England Grammar School in Brisbane. With his family background heavily involved in theatrical enterprises, McCallum began his lifelong association with the stage by appearing in amateur productions in Brisbane. His first stage part was at his father's theatre. In 1935, shortly before returning to the United Kingdom, he was given a bit part for the film Heritage, much of which was filmed in Canungra in South-East Queensland. He also appeared in a 1936 Brisbane Repertory Society revival of Hamlet (Princess Theatre, Woolloongabba). Later that same year he won a scholarship to study theatre at London's Royal Academy of Dramatic Art and in the years leading up to the Second World War he worked in British repertory, the Shakespeare Memorial Theatre and the Old Vic. His first appearance in the West End was at the Whitehall Theatre in Cornelius.

Following the war, during which he served in the A.I.F., McCallum worked for J. C. Williamson's as both producer and actor. He is remembered for such productions as The Wind and the Rain (as producer), and for his co-starring roles with Gladys Moncrieff in The Maid of the Mountains and Rio Rita. He also appeared in Susan and God, By Candlelight, Claudie, The Deep Blue Sea, Simon and Laura and Roar Like a Dove. Before returning to the United Kingdom in 1946, McCallum appeared as John Seldon in A Son Is Born opposite Peter Finch. In 1947 he was cast in his first British film, Root of All Evil, and provided the narration to the hit children's movie, Bush Christmas (which was filmed entirely in Australia). Later that same year, during the making of The Loves of Joanna Godden, he met actress Googie Withers. The two actors married in 1948, and the following year appeared together in the film Traveller's Joy. It was not until Waiting for Gillian (St James Theatre, London) in 1954, however, that they first acted together on stage. Other films in which McCallum appeared include: It Always Rains on Sunday, Miranda, Valley of Eagles, Woman in Question, Derby Day, Trent's Last Case, The Calendar and Port of No Escape.

When McCallum and Withers returned to Australia in 1958, the move was effectively permanent. While Withers continued to pursue her acting career, McCallum started to move his career more towards the production side of theatre. His first engagement was as assistant general manager for J. C. Williamson's, and soon afterwards, he began directing a number of productions for the firm including, The Piccadilly Bushman by Ray Lawler and the second of two simultaneously touring productions of My Fair Lady. McCallum became joint managing director of Williamson's in 1961 (with Sir Frank Tait) and four years later, following Tait's death, took over the position in his own right.

During the mid-1960s McCallum co-founded the film and television company Fauna Productions with Bob Austin and Lee Robinson. His role with the company often saw him involved as executive producer, writer and/or director. Among the company's television productions were Skippy 'the bush kangaroo' (1966-1968), Barrier Reef (1971-1972), Bailey's Bird (1977), Boney (1972-1973) and Shannon's Mob (1975-1976). The company also produced such films as The Intruders (1969, aka Skippy and the Intruders) and Attack Force Z (1982, starring Mel Gibson and Sam Neil). He directed and also wrote the screenplay for his most successful film, The Nickel Queen (1971), which starred his wife Googie Withers, daughter Joanna McCallum and radio broadcaster John Laws.

John McCallum was honoured with a CBE in 1971 for his services to the performing arts. After that he continued to appear intermittently on the stage, most often with his wife. Among the more notable productions in which the two have performed together were: As It's Played (1974, Comedy Theatre, Melbourne) which he also wrote, directed and produced; The Kingfisher (1978) with Googie Withers (they revived this in 1988 with daughter Joanna); W. Somerset Maugham's comedy The Circle (1982, Australia and London); Stardust (1984, UK and Australia), which was specially written for McCallum and Withers by Ted Willis (McCallum produced the Australian tour); On Golden Pond (1990, UK); High Spirits (1993, Australia), which was designed by their son, Nicholas McCallum; An Ideal Husband (1996/1997, UK and Australia) and Lady Windermere's Fan (1997).

As an actor, John McCallum's film and television career includes appearances in: Bush Christmas (1947, Australia) with Chips Rafferty (McCallum's voice was heard as the narrator), The Long Memory (1952, UK), Melba (1953, UK), Devil on Horseback (1954, UK) and Smiley (1956, Australia). He has also featured in episodes for television series such as Elephant Boy, Boney and Barrier Reef. His more recent appearances have included a documentary in which he appears as himself, Forever Ealing (2002), and the 1987 mini-series Melba, in which he played Australian entrepreneur George Musgrove. Googie Withers played Lady Armstrong.

John McCallum passed away in a Sydney nursing home in February 2010 from leukaemia.