Sir Simon Russell Beale (born 12 January 1961) is an English actor. He has been described by The Independent as "the greatest stage actor of his generation". He has received various accolades, including two BAFTA Awards, three Olivier Awards, and a Tony Award. For his services to drama, he was knighted by Queen Elizabeth II in 2019.

Beale started his acting career at the Royal Shakespeare Company and National Theatre. He has received ten Laurence Olivier Award nominations, winning three awards for his performances in Volpone (1996), Candide (2000), and Uncle Vanya (2003). For his work on the Broadway stage he has received a Tony Award for Best Actor in a Play nomination for his performance as George in the Tom Stoppard play Jumpers in 2004. For his role as Henry Lehman in The Lehman Trilogy, he won the Tony Award for Best Actor in a Play and was nominated for an Olivier Award.

Beale made his film debut in Sally Potter's period drama Orlando (1992). He gained prominence for his roles in Persuasion (1995), Hamlet (1996), My Week with Marilyn (2011), The Deep Blue Sea (2011), Mary Queen of Scots (2018), Benediction (2021), and The Outfit (2022). In 2017, he portrayed Lavrentiy Beria in Armando Iannucci's The Death of Stalin, for which he received the British Independent Film Award for Best Supporting Actor.

Beale has also appeared in the television projects The Young Visiters (2003), Dunkirk (2004), and Vanity Fair (2018). He earned two British Academy Television Awards: one for Best Actor for A Dance to the Music of Time (1998), and the other for Best Supporting Actor for Henry IV, Part I and Part II (2012). From 2014 to 2016, he was part of the main cast of Showtime's Penny Dreadful, and since 2024 in House of the Dragon.