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

Richards won more Emmys than any other Seinfeld cast member, taking 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. 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. When 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 repeated 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 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's 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 Mad TV, 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]

Comedian Paul Mooney also cited the incident as a key factor leading to his decision to remove the racial slur from his own live performances.[26]

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". He 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, he 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.[27] In 2012, Richards appeared in comedy web series Comedians in Cars Getting Coffee, hosted by Jerry Seinfeld.[28] In 2014, he appeared as the president of Crackle in a trailer for Season 5. Seinfeld said the trailer's storyline would be expanded on in one of the episodes. In the comedy book SuperMega Saves the Troops written by Matt Watson and Ryan Magee, Michael Richards was a key character as an undercover spy.

Richards played Frank in the sitcom Kirstie, costarring Kirstie Alley and Rhea Perlman. It premiered on TV Land on December 4, 2013[7] and was canceled after one season.[29]