Matthew Lyn Lillard (born January 24, 1970) is an American actor, director, and producer. His early film roles include the black comedy Serial Mom (1994) and the crime thriller Hackers (1995). He achieved a career breakthrough for his portrayal of Stu Macher in the slasher film Scream (1996), which bolstered Lillard into the mainstream as a scream king. Afterwards, he starred in prominent roles in SLC Punk! (1998), She's All That (1999), Thirteen Ghosts (2001), and Without a Paddle (2004).

He portrayed Norville "Shaggy" Rogers in the live-action movies Scooby-Doo (2002) and Scooby-Doo 2: Monsters Unleashed (2004), and then later voiced the character in several animated releases, serving as the voice of Shaggy since Casey Kasem retired from the role in 2009. Starting in the 2010s, Lillard was more frequently cast in dramatic roles, in films such as The Descendants (2011), Trouble with the Curve (2012), Match (2014), and Twin Peaks: The Return (2017). He also starred in the NBC series Good Girls (2018–2021).