Ronald Colman was the second son and fourth child of Charles Colman and his wife Marjory Read Fraser. He was educated at boarding school in Littlehampton, where he discovered he enjoyed acting. He intended to study engineering at Cambridge University, but his father's sudden death from pneumonia made this financially impossible.

He became a well-known amateur actor, and was a member of the West Middlesex Dramatic Society in 1908-9. He made his first appearance on the professional stage in 1914.

After working as a clerk at the British Steamship Company in the City of London, he joined the London Scottish Regiment in 1909 and was among the first of the Territorial Army to fight in World War I. During the war, he served with fellow actors Claude Rains, Herbert Marshall and Basil Rathbone.

On October 31, 1914 at the Battle of Messines Colman was seriously wounded by shrapnel in his leg, which gave him a limp that he would attempt to hide throughout the rest of his acting career. He was invalided from the service in 1916.

Ronald Colman had first appeared in films in England in 1917 and 1919 under Cecil Hepworth, and subsequently with the old Broadwest Film Company in The Snow of the Desert. While appearing on stage in New York in La Tendress, Director Henry King saw him, and engaged him as the leading man in the 1923 film, The White Sister, opposite Lillian Gish, and was an immediate success.

Thereafter Colman virtually abandoned the stage for film. He became a very popular silent film star in both romantic and adventure films, and successfully made the transition to "talkies" because of his elegant and sonorous speaking voice. His dark hair and eyes and his athletic and riding ability (he did most of his own stunts until late in his career) led reviewers to describe him as a "Valentino type". He was often cast in similar, exotic roles.

His first major talkie success was in 1930, when he was nominated for the Academy Award for Best Actor for two roles — Condemned and Bulldog Drummond. He thereafter appeared in a number of notable films including Raffles, The Masquerader, Clive of India, A Tale of Two Cities in 1935, Under Two Flags, The Prisoner of Zenda and Lost Horizon in 1937, If I Were King in 1938, and The Talk of the Town in 1941.

He won the Best Actor Oscar in 1948 for A Double Life. At the time of his death, Colman was contracted by MGM for the lead role in Children of the Damned. However, Colman died and the film became a British production starring George Sanders, who had married Colman's widow, Benita Hume.