Tomlinson was born in Henley-on-Thames, Oxfordshire on 7 May 1917, to a well-respected London solicitor father. He attended Tonbridge School and left to join the Grenadier Guards for 16 months. His father then secured him a job as a clerk at Shell Mex House. His stage career grew from amateur stage productions to his 1940 film debut in Quiet Wedding. His career was interrupted when he entered Second World War service as a Flight Lieutenant in the RAF. During the war, he served as a flight instructor in Canada and made three films. His flying days continued after the war and he crashed a Tiger Moth plane near his back garden after he lost consciousness while flying. David Tomlinson was known to generations of children for his role as George Banks, head of the Banks family, in the 1964 Disney film Mary Poppins. Mary Poppins brought Tomlinson continued work with Disney, asking him to appear in The Love Bug (1968) and Bedknobs and Broomsticks (1971). Throughout the rest of Tomlinson’s film career, he never steered far from comedies. He retired from acting in 1980 to spend more time with his family; however, the enduring popularity of Mary Poppins ensured that he remained well-known.

Tomlinson was first married to Mary Lindsay Hiddingh, daughter of L. Seton Lindsay, the vice president of the New York Life Insurance Company. She had been widowed in 1941 when her husband, Major A.G. Hiddingh, was killed in action, leaving her to care for their two young sons. Tomlinson married Mary in September 1943. She committed suicide on 2 December 1943, when she jumped from a hotel in New York City, while holding her sons’ (his stepsons’) hands. Tomlinson’s second wife was actress Audrey Freeman, whom he married on 17 May 1953, and the couple remained together for 47 years until his death. They had four sons: David Jr., William, Henry and James. Tomlinson died peacefully in his sleep at King Edward VII Hospital, Westminster, at 4 a.m. on 24 June 2000, after suffering from a sudden stroke. He was 83 years old. He was interred at his estate grounds in Mursley, Buckinghamshire.