Simon Phillip Hugh Callow (born 15 June 1949) is an English actor. Known as a character actor on stage and screen, he has received numerous accolades including an Olivier Award and Screen Actors Guild Award as well as nominations for two BAFTA Awards. He was made a Commander of the Order of the British Empire (CBE) for his services to acting by Queen Elizabeth II in 1999.

Callow rose to prominence originating the title role of Wolfgang Amadeus Mozart in the 1979 Peter Shaffer play Amadeus, for which he received a Laurence Olivier Award for Best Actor in a Supporting Role nomination. Callow joined the Miloš Forman 1984 film adaptation, this time portraying Emanuel Schikaneder. In 1992, Callow won the Laurence Olivier Award for Best Director of a Musical for Carmen Jones. As an actor, he won acclaim for his comedic roles in A Room with a View (1985) and Four Weddings and a Funeral (1994) earning BAFTA Award for Best Actor in a Supporting Role for each. Other notable roles include in Maurice (1987), Howards End (1992), Shakespeare in Love (1998), and The Phantom of the Opera (2004).

His television roles include Tom Chance in the Channel 4 series Chance in a Million (1984) and The Duke of Sandringham in the series Outlander from 2014 to 2016. He portrayed Napoleon in The Man of Destiny (1981), and Charles Dickens in numerous television projects. He has also appeared on numerous shows such as Midsomer Murders, Rome, Angels in America, Doctor Who, Galavant, Hawkeye, and The Witcher.