Sir Charles Spencer Chaplin was the most famous actor in early Hollywood cinema, and later also a notable director. His principal character was "The Tramp": a vagrant with the refined manners and dignity of a gentleman who wears a tight coat, oversized pants and shoes, a derby or bowler hat, a bamboo cane, and his signature square mustache. Chaplin was one of the most creative personalities in the silent film era; he acted in, directed, scripted, produced, and eventually scored his own films.

Chaplin was born in Walworth, London, England to Charles, Sr. and Hannah Harriette Hill, both Music Hall entertainers. His parents separated soon after his birth, leaving him in the care of his increasingly unstable mother. In 1896, she was unable to find work; Charlie and his older half-brother Sydney had to be left in the workhouse at Lambeth, moving after several weeks to Hanwell School for Orphans and Destitute Children. His father died an alcoholic when Charlie was 12, and his mother suffered a mental breakdown, and was eventually admitted to the Cane Hill Asylum near Croydon. She died in 1928.

Charlie first took to the stage when, aged 5, he performed in Music Hall in 1894, standing in for his mother. As a child, he was confined to a bed for weeks due to a serious illness, and, at night, his mother would sit at the window and act out what was going on outside. In 1900, aged 11, his brother helped get him the role of a comic cat in the pantomime Cinderella at the London Hippodrome. In 1903 he appeared in Jim, A Romance of Cockayne, followed by his first regular job, as the newspaper boy Billy in Sherlock Holmes, a part he played into 1906.

This was followed by Casey's Court Circus variety show, and, the following year, he became a clown in Fred Karno's Fun Factory slapstick comedy company. According to immigration records, he arrived in the USA with the Karno troupe on October 2, 1912. In the Karno Company was Arthur Stanley Jefferson, who would later become known as Stan Laurel. Chaplin and Laurel wound up sharing a room in a boarding house. Stan Laurel returned to England but Chaplin remained in the USA. His act was seen by film producer Mack Sennett, who hired him for his studio, the Keystone Film Company.

While Chaplin initially had difficulty adjusting to the Keystone style of film acting, he soon adapted and flourished in the medium. This was made possible in part by Chaplin developing his signature Tramp persona, and by eventually earning directorship and creative control over his films, which enabled him to become Keystone's top star and talent.

In 1919 he founded the United Artists studio with Mary Pickford, Douglas Fairbanks and D. W. Griffith.

Although "talkies" became the dominant mode of moviemaking soon after they were introduced in 1927, Chaplin resisted making a talkie all through the 1930s. It is a tribute to Chaplin's versatility that he also has one film credit for choreography for the 1952 film Limelight, and one credit as a singer for the title music of the 1928 film The Circus. The best-known of several songs he composed is "Smile", famously covered by Nat King Cole, among others.

His first sound picture, The Great Dictator (1940) was an act of defiance against Adolf Hitler and fascism, filmed and released in the United States one year before it abandoned its policy of isolationism to enter World War II. Chaplin played a fascist dictator clearly modeled on Hitler (also with a certain physical likeness), as well as a Jewish barber cruelly persecuted by the Nazis. Hitler, who was a great fan of movies, is known to have seen the film twice (records were kept of movies ordered for his personal theater). After the war and the uncovering of the Holocaust, Chaplin stated that he would not have been able to make such jokes about the Nazi regime had he known about the actual extent of the pogrom.

Chaplin's political sympathies always lay with the left. Several of his movies, notably Modern Times (1936), depict the dismal situation of workers and the poor.

Although Chaplin had his major successes in the United States, he retained his British nationality. During the era of McCarthyism, Chaplin was accused of "un-American activities" as a suspected communist; and J. Edgar Hoover, who had instructed the FBI to keep extensive files on him, tried to end his United States residency.

In 1952, Chaplin left the US for a trip to England; Hoover learned of it and negotiated with the INS to revoke his re-entry permit. Chaplin then decided to stay in Europe, and made his home in Vevey, Switzerland. He briefly returned to the United States in April 1972 to receive an Honorary Oscar.

Chaplin won the honorary Oscar twice. When the first Oscars were awarded on May 16, 1929, the voting audit procedures that now exist had not yet been invented, and the categories were still very fluid. When it became apparent that Chaplin, who had been nominated for Best Actor and Best Comedy Direction, had failed to win either award for his movie The Circus, the Academy decided to give him a special award "for versatility and genius in acting, writing, directing and producing The Circus". The other film to receive a special award that year was The Jazz Singer.

Chaplin's second honorary award came 44 years later in 1972, and was for "the incalculable effect he has had in making motion pictures the art form of this century". He came out of his exile and collected his award less than a month before the death of J. Edgar Hoover. Chaplin was also nominated without success for Best Picture, Best Actor, and Best Original Screenplay for The Great Dictator, and again for Best Original Screenplay for Monsieur Verdoux (1947).

In 1973, he received an Oscar for the Best Music in an Original Dramatic Score for the 1952 film Limelight, which co-starred Claire Bloom. The film also features a cameo with Buster Keaton, which was the first and last time the two great comedians ever appeared together. Because of Chaplin's difficulties with McCarthyism, the film did not open in Los Angeles when it was first produced. This criterion for nomination was not fulfilled until 1972.

His final films were A King in New York (1957) and A Countess from Hong Kong (1967), starring Sophia Loren and Marlon Brando.

Chaplin died on Christmas Day, 1977 in Vevey, Switzerland at age 88, and was interred in Corsier-Sur-Vevey Cemetery in Corsier-Sur-Vevey, Vaud. On March 1, 1978, his body was stolen in an attempt to extort money from his family. The plot failed. The robbers were captured, and the body was recovered 11 weeks later near Lake Geneva.