Michael Richards

Richards with Jerry Seinfeld at the 44th Primetime Emmy Awards in 1992

In 1989, Richards was cast as Cosmo Kramer in the NBC television series Seinfeld, which was created by fellow Fridays cast member Larry David and comedian Jerry Seinfeld. Although it got off to a slow start, by the mid-1990s the show had become one of the most popular sitcoms in television history. The series ended its nine-year run in 1998 at No. 1 in the Nielsen ratings. In the setting of Seinfeld, Kramer is usually referred to by his last name only and is the neighbor of the show's eponymous character. Kramer's first name, Cosmo, was revealed in the sixth-season episode "The Switch".

Richards won more Emmys than any other cast member on Seinfeld. He took home the award for Outstanding Supporting Actor in a Comedy Series in 1993, 1994 and 1997.

Starting in 2004, he and his fellow Seinfeld cast members provided interviews and audio commentaries for the Seinfeld DVDs, but Richards stepped down from providing audio commentary after Season 5, though he continued to provide interviews.

In 2000, after the end of Seinfeld, Richards began work on a new series for NBC, his first major project since Seinfeld's finale. The Michael Richards Show, for which Richards received co-writer and co-executive producer credits, was conceived as a comedy/mystery starring Richards as a bumbling private investigator. After the first pilot failed with test audiences, NBC ordered that the show be retooled into a more conventional, office-based sitcom before its premiere. After a few weeks of poor ratings and negative reviews, it was cancelled.

During a performance on November 17, 2006, at the Laugh Factory in Hollywood, California, Richards launched into a racist rant in response to reported heckling and interruptions from a small group of black audience members. Richards was recorded shouting "He's a nigger!" several times and making references to lynching and the Jim Crow era.[6][16][17][18][19] Kyle Doss, a member of the group that Richards addressed, said the group had arrived in the middle of the performance and were "being a little a loud". According to Doss:

[Richards] said, "Look at the stupid Mexicans and blacks being loud up there." That's the first thing he said. And then he kept on with his bit. And, then, after a while, I told him, "My friend doesn't think you're funny." And then when I told him that, that's when he flipped me off and said, "F-you N-word." And that's how it all started.

— Kyle Doss, Interview on The Situation Room[20]

Three days after the incident, Richards made a public apology via satellite on the Late Show with David Letterman, saying: "For me to be at a comedy club and to flip out and say this crap, I'm deeply, deeply sorry. I'm not a racist, that's what's so insane about this."[21] Many studio audience members laughed as Richards began his unscripted explanation and apology, leading show guest Jerry Seinfeld to reprimand them, saying, "Stop laughing. It's not funny." Richards said he had been trying to defuse the heckling by being even more outrageous, but it had backfired. He later called civil rights leaders Al Sharpton and Jesse Jackson to apologize.[20][22] He also appeared as a guest on Jackson's syndicated radio show.[23] Doss stated that he did not accept Richards' apology, saying, "If he wanted to apologize, he could have contacted... one of us out of the group. But, he didn't. He apologized on camera just because the tape got out."[22][24]

The incident was parodied on several TV shows, including MadTV, Family Guy, South Park, Extras and Monday Night Raw. In an episode of Curb Your Enthusiasm, Richards appeared as himself and poked fun at the incident. In a 2012 episode of Seinfeld's web series Comedians in Cars Getting Coffee, Richards explained that the outburst still haunted him, and was a major reason for his retirement from stand-up.[25]

Richards played himself in Episode 2 of Season 1 "The Flirt Episode" (1992) of the HBO series The Larry Sanders Show. He also had a cameo role in the comedy thriller film So I Married an Axe Murderer, credited as "insensitive man". Richards played radio station employee Doug Beech in Airheads and co-starred with Jeff Daniels as an actor pretending to be a lawyer in 1997's Trial and Error. He also made guest appearances on Miami Vice, Night Court and Cheers. In 2007, Richards voiced character Bud Ditchwater in the animated film Bee Movie, which starred, and was produced by, Jerry Seinfeld. In 2009, Richards and the other main Seinfeld cast members appeared in the seventh season of Curb Your Enthusiasm.[26] In 2012, Richards appeared in comedy web series Comedians in Cars Getting Coffee, hosted by Jerry Seinfeld.[27] In 2014, Richards appeared as the president of Crackle in a trailer for Season 5. Seinfeld said the storyline of the trailer would be expanded on in one of the episodes.

Richards played the role of Frank in the sitcom Kirstie, costarring Kirstie Alley and Rhea Perlman, premiering on TV Land on December 4, 2013.[7] The show was canceled after one season.[28]