Knight additionally acted in the films Dead Again (1991), JFK (1991), Basic Instinct (1992), To Die For (1995), Space Jam (1996), For Richer or Poorer (1997), and Rat Race (2001).

He provided the voices of Tantor in Tarzan (1999), Al McWhiggin in Toy Story 2 (1999), and The Elf Elder in Tom and Jerry: The Lost Dragon (2014).

[3] Knight appeared in various films in the late 1980s and early 1990s, including Dirty Dancing (1987), Born on the Fourth of July (1989), JFK (1991) and Basic Instinct (1992).

He played the mailman Newman, Jerry's neighbor and nemesis, in Seinfeld, and Officer Don Orville, Sally's love interest, in 3rd Rock from the Sun.

He also appeared as a regular on two sketch comedy series, The Edge for Fox and Assaulted Nuts for Cinemax and Channel 4 in the United Kingdom.

Knight has done voice work for numerous animations, including the black cat Mr. Blik in Catscratch, Igor in Toonsylvania, the dragon Dojo Kanojo Cho in the Kids' WB!

He made guest appearances on Billy & Mandy's Jacked-Up Halloween as Jack O'Lantern, Dilbert as the Security Guard, and Brandy & Mr. Whiskers as Mr. Cantarious the snail.

In February 2014, Knight reprised the character Newman, during one commercial during the Super Bowl, alongside Jerry Seinfeld and Jason Alexander.

Knight married makeup artist Paula Sutor on May 26, 1996, in a ceremony held in the home of fellow Seinfeld cast member Michael Richards.

[14] Ahead of the 2020 United States presidential election, Knight appeared in an advertisement that examined "ethical breaches" of mail workers in the U.S. and the lack of support they received from the government.