Saturday Night Live’s producers, especially Lorne Michaels, have famously and dramatically banned for life several celebrities from ever appearing on the television show. Reasons for these bans vary, as sometimes they can be seen as a rational response to a star’s grossly innappropriate on-stage behavior, while at other times the reasons are harder to understand as they stem from far more mild, or even superficial transgressions.
* Louise Lasser, who hosted at the end of the first season on July 24, 1976, was the first host banned by the producers. Lasser was said to be going through personal problems at the time and was reportedly nearly incoherent throughout the broadcast.
Note: This episode was such a disappointment to producer Lorne Michaels that it was also not repeated on NBC, although it has appeared in syndication since 1981.
* Charles Grodin has never been asked back to host after he gave a clumsy performance. In October 1977, on his one appearance on the show, Grodin missed rehearsal, stumbled his way through the show, and ad-libbed many of his lines.
* On December 17, 1977, Elvis Costello and the Attractions performed as a last-minute replacement for the Sex Pistols, who were unable to obtain passports. NBC and the show’s producer Lorne Michaels didn’t want the band to perform “Radio Radio”, since the song protests the state of the media. The band defied them by beginning to play their song “Less Than Zero”, stopping, with Costello telling the audience that there was no reason to do that song, and telling the band to play “Radio Radio” instead. It infuriated Michaels because it put the show off schedule, and the band were barred from performing again.
Note: Eventually Lorne Michaels put his grievances aside, lifting the ban, and Elvis Costello would appear as musical guest in 1989 and 1991. He also reprised his performance of “Radio Radio” with the Beastie Boys for a 25th anniversary special aired on September 26, 1999.
* Frank Zappa was banned from the show after his hosting stint on October 21, 1978. His distinct sense of humor made him unpopular with the cast and crew. During his performance, he made a habit of reading cue-cards and mugging for the camera, and many cast members (save for John Belushi) deliberately stood far from him during the goodnights.
* The April 14, 1979 episode of the show hosted by Milton Berle resulted in him being banned due to his habit of upstaging other performers, overacting, mugging for the camera, insertion of “classic” comedy bits and his maudlin performance of “September Song.”
Note: This episode was also barred from rebroadcast for over twenty years until February 2003, when an edited version was shown on E!; it twice aired in full in Canada on The Comedy Network in 2001. Lorne Michaels felt that the broadcast, and Berle in particular, brought the show down.
* Fear was banned from playing again after the 1981 Halloween episode. With Donald Pleasence as host, the band played that night by request from Fear fan John Belushi, and they proceeded to play offensive songs (“I Don’t Care About You” and “Beef Balogna” among others) and bus in “dancers”. The band also used obscene language and the dancers destroyed the set with their slam dancing onstage. The situation was out of control to the extent that the damage of studio equipment forced Dave Wilson to end the three-song performance by cutting the audio and video to a commercial as they started to play “Let’s Have a War” .
Note: The episode has not been rebroadcast on NBC.
* On November 13, 1982, host Robert Blake was very dissatisfied with the scripts that he received throughout the week. He was barred from ever performing on the show again after he crumpled up a script presented to him by cast member and writer Gary Kroeger and threw it back in his face.
* A proposed banning of a frequent guest was left in the hands of viewers on November 20, one week later. Andy Kaufman, who had appeared in the very first episode in 1975 and periodically thereafter, was the subject of a viewer poll to decide if Kaufman should be allowed to stay or be banned for life from the show. Viewers had to call a 900 number to cast their vote. They decided to kick him off, and Kaufman never returned to the show.
Note: It was actually Kaufman who pitched the idea to Dick Ebersol weeks before, and Ebersol used the idea after he had a fight with Kaufman.
* The influential alternative group The Replacements were banned from the show due to their behavior after they appeared on the show on January 18, 1986 to promote their first album with Sire Records, Tim. When it came time for them to perform their first number, “Bastards of Young,” they were intoxicated and several cast members were unsure whether they could perform. Lead singer Paul Westerberg would further aggravate circumstances when he yelled “fuck” to the crowd during “Bastards of Young”. The band went on to perform one more song, “Kiss Me on the Bus”.
Note: In subsequent rebroadcasts of this episode, the “fuck” is censored out of “Bastards of Young.” Lead singer Paul Westerberg returned as a solo musical guest and Bassist Tommy Stinson is featured on a playbill during commercial breaks during the most recent season.
* Steven Seagal, who hosted on April 20, 1991, was also banned from hosting because of his difficulty in working with the cast and crew.
Note: They made note of the occasion almost a year and a half later, as during Nicolas Cage’s monologue on September 26, 1992, Nicolas spoke with Lorne backstage, saying, “…they probably think I’m the biggest jerk who’s ever been on the show!” to which Lorne replied, “No, no. That would be Steven Seagal.”
* SinÃ©ad O’Connor was banned from appearing on SNL again after her peformance on October 3, 1992. In her second set of the show, she performed an a cappella version of Bob Marley’s “War”. During the word “evil”, she picked up a picture of Pope John Paul II, ripped it up, and shouted, “Fight the real enemy!” Dave Wilson immediately turned off the “applause” cue and the audience reacted with complete silence. NBC received many complaints about this within a matter of minutes. At the end of the show, host Tim Robbins, who was raised Catholic, refused to give O’Connor the customary “thanks” for being the musical guest. .
Note: To this day, NBC refuses to lend out the footage of the performance to any media outlet, and they edited out the incident from the syndicated version of the episode, replacing it with footage from the dress rehearsal taped earlier in the evening. It was finally released in 2003, with an explanation from Lorne Michaels, on Disc 4 of the Saturday Night Live – 25 Years of Music DVD set.
* Cypress Hill were banned from appearing on SNL again after their performance as the musical guest on the October 2, 1993 episode, where DJ Muggs lit up a marijuana joint on-air and the band trashed their instruments after playing their second single “I Ain’t Goin’ Out Like That.”
* Martin Lawrence was banned from the show after his opening monologue on the February 19, 1994 episode included comments about female genitalia.
Note: The monologue has been edited out in both the network repeats and syndicated version, with just a graphic describing in general what Lawrence had said. The graphic also told viewers that it was a lively monologue and it almost cost many SNL employees their jobs. 
* Chevy Chase was banned from hosting the show again after the February 15, 1997 episode due to his verbal abuse of the cast and crew during the week. Chase became notorious for his treatment of certain cast members when hosting past episodes, particularly his remarks to openly gay cast member Terry Sweeney.
Note: In 1985, Chase suggested that a perfect skit for Sweeney would be one in which he plays an AIDS victim who gets weighed every week. Chase’s abusive behavior during the 1985 episode and other episodes are detailed in the Live From New York: An Uncensored History of Saturday Night Live book.
Further Note: Although Chase was banned from hosting the show in 1997, he appeared on the 25th anniversary special in 1999, was interviewed for the 2005 special Live From New York: The First Five Years of Saturday Night Live, and cameoed in two episodes (one hosted by Bill Murray in 1999 and another hosted by Seann William Scott in 2001).
* Adrien Brody became the latest person banned on May 10, 2003. He came out to introduce reggae musician Sean Paul, while wearing Rastafarian attire including faux dreadlocks. Without any prior notice, Brody began rambling in a Jamaican accent for close to 45 seconds before finally introducing the act incorrectly, misannouncing “Sean Paul” as “Sean John.”
Note: Michaels is notorious for his dislike of improvisation and unannounced performances, and was furious with Brody for not obtaining clearance before performing this “monologue.”