His film work includes Chip Sutphin in Serial Mom (1994), Emmanuel "Cereal Killer" Goldstein in Hackers (1995), Stu Macher in Scream (1996), Stevo in SLC Punk!

U.S. entertainment publication The Hollywood Reporter stated that he had entered "his Renaissance era" in popular culture, noting that the movie had the third highest ever domestic box office return during its opening weekend for a horror film.

[2][3] While much of his work is comedic in nature, Lillard has also given dramatic performances in projects such as The Descendants (2011), Trouble with the Curve (2012), Match (2014), and Twin Peaks: The Return (2017).

He later attended Fullerton College and then went to the American Academy of Dramatic Arts in Pasadena, California, with fellow actor Paul Rudd.

The following year he was cast in five films, including Hackers, a thriller about a group of high school kids who thwart a multimillion-dollar corporate extortion conspiracy.

In 2016, Lillard landed the recurring role of FBI undercover agent Luke Goshen in the Amazon Series, Bosch.

U.S. entertainment publication The Hollywood Reporter stated that he had entered "his Renaissance era" in popular culture, noting that the movie had the third highest ever domestic box office return during its opening weekend for a horror film.

[21] In January 2025, it was announced he is returning to the Scream franchise for its seventh entry, having previously played Stuart ‘Stu’ Macher in the first 1996 movie.

[22] Lillard was one of the co-founders of Beadle and Grimms, a company that publishes licensed expanded products, usually of a limited edition, from Wizards of the Coast games including Dungeons and Dragons and Magic: The Gathering.

[25] In October 2005, he participated in a Dungeons & Dragons tournament, against members of the Quest Club Gaming Organization, at the Magic Castle in Hollywood, California.