David Matthew Macfadyen (born 17 October 1974) is an English actor. Known for his performances on stage and screen, he gained prominence for his role as Mr. Darcy in Joe Wright's Pride & Prejudice (2005). He starred as Tom Wambsgans in the HBO drama series Succession (2018–2023), for which he has received two Primetime Emmy Awards, two BAFTA Awards, and a Screen Actors Guild Award.

Macfadyen is also known for his roles in films such as Death at a Funeral (2007), Frost/Nixon (2008), Anna Karenina (2012), The Assistant (2019), and Operation Mincemeat (2021). He made his television debut in 1998 as Hareton Earnshaw in Wuthering Heights. He portrayed Tom Quinn in the BBC One spy series Spooks (2002–04, 2011), and Inspector Edmund Reid in the BBC mystery series Ripper Street (2012–2016). He also starred as Henry Wilcox in Kenneth Lonergan's miniseries Howards End and Charles Ingram in the Stephen Frears' limited series Quiz (2020).