Simon John Pegg (né Beckingham; born 14 February 1970) is an English actor, comedian and screenwriter. He came to prominence in the UK as the co-creator of the Channel 4 sitcom Spaced (1999–2001), directed by Edgar Wright. He and Wright co-wrote the films Shaun of the Dead (2004), Hot Fuzz (2007), and The World's End (2013), known collectively as the Three Flavours Cornetto trilogy, all of which saw Wright directing and Pegg starring alongside Nick Frost. Pegg and Frost also wrote and starred in the sci-fi comedy film Paul (2011).

Pegg is one of the few performers to have achieved what Radio Times calls the "Holy Grail of Nerd-dom", having played popular supporting characters in Doctor Who (2005), Star Trek as Montgomery "Scotty" Scott (2009–2016), and Star Wars: The Force Awakens (2015). He starred as Benji Dunn in six Mission: Impossible films, beginning with Mission: Impossible III (2006) and ending with Mission: Impossible – The Final Reckoning (2025). He has also provided the voice of Buck in the Ice Age film series (2009–present).