He is best known for playing Norm Peterson on the NBC sitcom Cheers (1982–1993), which earned him six consecutive nominations for the Primetime Emmy Award for Outstanding Supporting Actor in a Comedy Series.

Wendt also appeared in the films Airplane II: The Sequel (1982), No Small Affair (1984), Fletch (1985), The Little Rascals (1994), Spice World (1997), Outside Providence (1999), Santa Buddies (2009), and Sandy Wexler (2017).

[4] Wendt is an uncle of actor and former SNL writer and cast member Jason Sudeikis, his sister Kathryn's son.

[6] He attended the University of Notre Dame until he was expelled after receiving a 0.00 GPA during his first semester of junior year, reportedly due to challenges associated with living in an off-campus apartment without transportation during winter.

For his work on Cheers, Wendt earned six Primetime Emmy Award nominations for Best Supporting Actor in a Comedy Series.

His first appearance on Saturday Night Live was in a season 11 (1985–1986) episode where he shared hosting duties with director Francis Ford Coppola.

In the early 1990s, Wendt made cameo appearances on several episodes of SNL as Bob Swerski, one of the Chicago Superfans (along with cast members Chris Farley, Mike Myers, Robert Smigel, and one-time host, Joe Mantegna).

In the same year as his Frasier guest appearance, Wendt played the bartender to Ted Danson's character in Becker (the inverse of their relationship on Cheers).

In 1994, he appeared in the film Man of the House as Chet Bronski, the stepfather of Norman (Zachary Browne), and starred with Chevy Chase, Jonathan Taylor Thomas and Farrah Fawcett.

In early 1997, Wendt joined the cast of the NBC sitcom The Naked Truth as Les Polonsky, the new owner of the celebrity tabloid where the series' main characters worked.

In 2003, Wendt appeared as a celebrity fisherman in the music video for Cobra Verde's "Riot Industry" along with Rudy Ray Moore (of "Dolemite" fame) and The Minutemen's Mike Watt.

Wendt appeared in a production of Hairspray, reprising his role as Edna Turnblad, from September 8 to October 9, 2010,[12] at the Charlottetown Festival in Prince Edward Island, Canada.

Wendt was set to play the role of Pap in the Hank Williams bio musical Lost Highway at the Merry-Go-Round Playhouse in Auburn, New York.

[13] Wendt and Robert Smigel reprise their roles from SNL as the Chicago Superfans, who encounter quarterback Aaron Rodgers.

From November 6, 2013, to January 19, 2014, Wendt starred in Never Too Late, a comedy with his wife, actress Bernadette Birkett, at New Theatre Restaurant in Overland Park, Kansas.

[15] In 2015, Wendt starred opposite his former Second City co-star Tim Kazurinsky in Bruce Graham's new comedy Funnyman at Northlight Theatre.

[17] Wendt starred as Willy Loman in Death of a Salesman at St. Jacob's Country Playhouse in Waterloo, Ontario, Canada, from October 18 to November 4, 2017.