This is an overview of 1921 in film, including significant events, a list of films released and notable births and deaths.

The top nine films released in 1921 by U.S. gross are as follows:

• January 21 – The silent comedy drama The Kid, written by, produced by, directed by and starring Charlie Chaplin (in his Tramp character) – his first full-length film as a director – and featuring Jackie Coogan, is released in the United States. It is the year's second-highest-grossing film.
• March 6 – The silent epic war film The Four Horsemen of the Apocalypse, adapted for the screen by June Mathis, is released in the United States. It is the year's highest-grossing film (and the sixth-best-grossing silent film of all time), propels Rudolph Valentino to stardom and inspires a tango craze and a fashion for gaucho pants.
• August 29 – Broadway's first $1 million theatre, Loew's State opens.
• September 5 – Popular comedian Roscoe "Fatty" Arbuckle attends a party at the St. Francis Hotel, San Francisco, during which actress Virginia Rappe is fatally injured; although he is eventually acquitted of rape and manslaughter, the scandal derails his career.
• October 21 – George Melford's silent film The Sheik, which enhances leading actor Rudolph Valentino's international reputation as a Latin lover, is premiered in Los Angeles. Within the first year of its release, it exceeds $1 million in ticket sales.
• October 26 – The Chicago Theatre, which will be the oldest surviving French-style Baroque Revival grand movie palace, opens.
• The experimental short documentary film Manhatta is shot by painter Charles Sheeler and photographer Paul Strand in New York City.

United States unless stated.

• Harold Lloyd (1913–1938)
• Charlie Chaplin (1914–1940)
• Lupino Lane (1915–1939)
• Buster Keaton (1917–1944)
• Laurel and Hardy (1921–1945)

• Aesop's Film Fables (1921–1934)
• Felix the Cat (1919–1936)
• Koko the Clown (1919–1963)

• January 3 – John Russell, actor (died 1991)
• January 10 - George Robotham, American stuntman and actor (died 2007)
• January 11 - Kathleen Byron, English actress (died 2009)
• January 17 - Herb Ellis, American character actor (died 2018)
• January 26 – Elisabeth Kirkby, British-born Australian actress, producer and director
• January 27 – Donna Reed, actress (died 1986)
• January 31
  • Carol Channing, musical actress (died 2019)
  • Mario Lanza, singer and actor (died 1959)
• February 1 – Peter Sallis, actor (died 2017)
• February 8 – Lana Turner, actress (died 1995)
• February 16 – Vera-Ellen, actress, dancer (died 1981)
• February 19 – Ann Savage, actress (died 2008)
• February 22 – Giulietta Masina, actress (died 1994)
• February 23 - Jack Rader, American actor
• February 24 – Abe Vigoda, actor (died 2016)
• February 26 – Betty Hutton, actress (died 2007)
• March 3 – Diana Barrymore, actress (died 1960)
• March 4 – Joan Greenwood, actress (died 1987)
• March 5 - Jo de Winter, American actress (died 2016)
• March 8 – Alan Hale Jr., actor, restaurateur (died 1990)
• March 10 – Charlotte Zucker, actress, mother of Jerry Zucker and David Zucker (died 2007)
• March 12 – Gordon MacRae, actor, singer (died 1986)
• March 21 - Logan Ramsey, American character actor (died 2000)
• March 23 – Geoffrey Chater, English actor (died 2021)
• March 25
  • Nancy Kelly, American actress (died 1995)
  • Simone Signoret, French actress (died 1985)
• March 26 – Julie Harris, English costume designer (died 2015)
• March 28 – Dirk Bogarde, English actor (died 1999)
• April 1 – Arieh Elias, Israeli actor (died 2015)
• April 3 – Jan Sterling, American actress (died 2004)
• April 7 – Bill Butler, American cinematographer (died 2023)
• April 10 – Chuck Connors, American actor (died 1992)
• April 16 – Peter Ustinov, British actor (died 2004)
• April 23
  • Janet Blair, American actress (died 2007)
  • Gerald Campion, English actor (died 2002)
• April 29 – Tommy Noonan, American actor, screenwriter, producer (died 1968)
• May 2 – Satyajit Ray, Indian filmmaker (died 1992)
• May 16 - Harry Carey Jr., American actor (died 2012)
• May 23
  • Grigori Chukhrai, Ukrainian film director (died 2001)
  • Ray Lawler, Australian actor
• May 30 - Jamie Uys, South African film director (died 1996)
• May 31 – Alida Valli, actress (died 2006)
• June 8
  • Sheila Ryan, actress (died 1975)
  • Alexis Smith, actress (died 1993)
• June 18 – Wesley Lau, actor (died 1984)
• June 19 – Louis Jourdan, actor (died 2015)
• June 21
  • Judy Holliday, born Judith Tuvim, actress (died 1965)
  • Jane Russell, actress (died 2011)
• July 2 - Maria Britneva, Russian-British actress (died 1994)
• July 3 – Susan Peters, actress (died 1952)
• July 5 – Patricia Wright, American former actress
• July 6 – Nancy Reagan, born Anne Robbins, actress and First Lady of the United States (died 2016)
• July 10 – Jeff Donnell, American actress (died 1988)
• July 17 – František Zvarík, Slovakian actor (died 2008)
• July 21 - Al Checco, American actor (died 2015)
• July 23 – Robert Brown, actor (died 2003)
• August 3 – Marilyn Maxwell, actress (died 1972)
• August 8 – Esther Williams, actress, swimmer (died 2013)
• August 11 - Tad Horino, American actor (died 2002)
• August 19
  • Pasquale Cajano, Italian-American actor (died 2000)
  • Gene Roddenberry, screenwriter and producer (died 1991)
• August 28 – Nancy Kulp, actress, comedienne (died 1991)
• September 8 – Harry Secombe, actor, singer (died 2001)
• September 27 – Miklós Jancsó, Hungarian director (died 2014)
• September 30 – Deborah Kerr, actress (died 2007)
• October 1 - James Whitmore, American actor (died 2009)
• October 5 - Nikolay Dupak, Soviet-Russian actor (died 2023)
• October 12 - Kenneth Griffith, Welsh actor and documentary filmmaker (died 2006)
• October 13 – Yves Montand, singer, actor (died 1991)
• November 3 – Charles Bronson, actor (died 2003)
• November 5 – Moritz Yomtov, screenwriter (died 1992)
• November 8 – Walter Mirisch, American film producer (died 2023)
• November 14 - Brian Keith, American actor (died 1997)
• November 21 – Vivian Blaine, actor, singer (died 1995)
• November 22 – Rodney Dangerfield, actor, comedian (died 2004)
• November 23 – Fred Buscaglione, Italian actor and singer (died 1960)
• December 1 - Sylvia Kauders, American actress (died 2016)
• December 4 – Deanna Durbin, actress (died 2013)
• December 11 - Liz Smith, English character actress (died 2016)
• December 15 - Nikolai Lebedev, Soviet-Russian actor (died 2022)
• December 24 - Mickey Knox, American actor (died 2013)
• December 26 – Steve Allen, actor, composer, comedian, author (died 2000)

• February 8 – George Formby Sr, 45, British music hall entertainer who appeared in one film (pulmonary tuberculosis)^[18]
• May 17 – Karl Mantzius, 61, Danish actor, theatre director, writer
• June 5 – Georges Feydeau, 58, French playwright, many of whose plays were adapted for the screen (syphilis)^[19]
• June 11 - Frank R. Mills, 50, American stage and screen actor
• June 20 – George Loane Tucker, 49, American actor, screenwriter and director
• July 9 – Robert Broderick, 56, American stage and film actor
• September 9 – Virginia Rappe, 30,^[20] American actress
• September 17 – Van Dyke Brooke, 62, American actor, screenwriter and film director

• Richard Arlen – Ladies Must Live
• George Arliss – The Devil
• Mary Astor – Bullets or Ballots
• George Bancroft – The Journey's End
• Leslie Banks – Experience
• Anna-Lisa Baude – The Phantom Carriage
• Helga Brofeldt – The Phantom Carriage
• Julia Cæsar – The Phantom Carriage
• Louis Calhern – What's Worth While?
• Harry Carey Jr. – Desperate Trails
• Billie Dove – Get-Rich-Quick Wallingford
• Camilla Horn – Kean
• Selmer Jackson – The Supreme Passion
• Roger Livesey – The Four Feathers
• Carole Lombard – A Perfect Crime
• Fredric March – The Great Adventure
• Patsy Ruth Miller – One a Minute
• Mary Philbin – The Blazing Trail
• Basil Rathbone – Innocent
• Dorothy Revier – Life's Greatest Question
• Frances Robinson – Orphans of the Storm
• Athene Seyler – The Adventures of Mr. Pickwick
• Lilyan Tashman – Experience
• Fred Thomson – The Love Light
• Coy Watson Jr. – While the Devil Laughs

• List of American films of 1921

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