Rudd appeared in the films Clueless (1995), Halloween: The Curse of Michael Myers (1995), Romeo + Juliet (1996), Wet Hot American Summer (2001), Anchorman: The Legend of Ron Burgundy (2004), The 40-Year-Old Virgin (2005), Knocked Up (2007), I Love You, Man (2009), and This Is 40 (2012).

Rudd has also appeared in numerous television shows, including the sitcom Friends (2002–2004) as Mike Hannigan, and has featured as a guest host of Saturday Night Live multiple times.

He starred in the miniseries The Shrink Next Door (2021), and featured in the Hulu comedy series Only Murders in the Building (2023–2024), which earned him a nomination for a Primetime Emmy Award.

[7][8] They were both from London, with his father hailing from Edgware and his mother from Surbiton,[9][10] and both were descended from Ashkenazi Jewish immigrants who moved to England from Belarus, Poland and Russia.

[33] Rudd followed Clueless with supporting roles films such as in Halloween: The Curse of Michael Myers as Tommy Doyle, William Shakespeare's Romeo + Juliet, The Locusts, Overnight Delivery, The Object of My Affection, and 200 Cigarettes.

He played FBI Agent Ian Curtis in Benny Chan's 2000 Hong Kong action film Gen-Y Cops.

He guest-starred as a has-been 1990s rock star, Desmond Fellows, on the television series Veronica Mars, in the 2007 episode "Debasement Tapes."

He subsequently appeared in Apatow in 2007's Knocked Up as frustrated husband Pete, married to Leslie Mann's character,[34] co-starring with Jason Segel, Jonah Hill, Seth Rogen, and Jay Baruchel.

He narrated the 2007 edition of the long-running sports documentary series Hard Knocks, which featured the Kansas City Chiefs, whom he continues to support.

Rudd appeared as John Lennon in the comedy film Walk Hard: The Dewey Cox Story in 2007[33] and as a drug-addled surf instructor in Nicholas Stoller's Forgetting Sarah Marshall in 2008 with Jason Segel and Jonah Hill, both of which Apatow produced.

[33] He starred with Leslie Mann in the Knocked Up spinoff This Is 40,[34] directed and produced by Apatow, and reprised his role of Brian Fantana in Anchorman 2: The Legend Continues (2013).

In 2007, he starred in The Oh in Ohio and The Ten, which reunited him with David Wain and Michael Showalter,[36] and then in Over Her Dead Body with Eva Longoria the next year.

In his next comedy which he also wrote, Role Models, he and co-star Seann William Scott portray energy drink salesmen forced to perform community service in a child mentoring program.

[41] In 2012, Rudd signed to appear on four episodes of NBC's Parks and Recreation as Bobby Newport, a candidate for City Council and a rival of Amy Poehler's character Leslie Knope, a role for which he won the Critics' Choice Television Award for Best Guest Performer in a Comedy Series.

[51][52] Rudd returned alongside Evangeline Lilly in Avengers: Endgame (2019), which received critical acclaim and went on to become the highest-grossing film of all time.

He also lent his voice to a struggling actor named John in the animated comedy film Nerdland (2016), alongside Patton Oswalt.

[65] In 2006, he appeared in the Broadway production of Richard Greenberg's Three Days of Rain with Bradley Cooper and Julia Roberts at the Bernard Jacobs Theater.

In 2000–2001, Rudd was in a production of Long Day's Journey Into Night with Jessica Lange, Charles Dance and Olivia Colman, at the Lyric Theatre, London.

In 2001, he starred as Adam in the original London production of Neil LaBute's The Shape of Things, and again Off-Broadway for three months starting in October 2001.

'"[74] Since 2014, Rudd and fellow actor Jeffrey Dean Morgan have been co-owners of Samuel's Sweet Shop, a candy store in Rhinebeck, New York that they saved from closing when the previous owner, a friend of theirs, died unexpectedly.