After Will's father immediately leaves him after a brief yet uncomfortable visit, Will's speech to Uncle Phil was ad-libbed by Will Smith. James Avery (Phil Banks) was so moved by Smith's speech that he immediately hugged before the scene ended.
According to Will Smith in an interview, the reason for his character being named "Will Smith" was that, during the creation of the show, he and Alfonso Ribeiro were brainstorming names for their characters. Alfonso remarked that Will had to be careful in naming his character, as people would refer to him in public by that name for the rest of his life, and suggested that he name the character "Will Smith".
As it required on-location shooting, only one shot of Jazz being thrown out of the house was done (with only a few exceptions). Therefore, to avoid continuity errors, it is made sure that Jazz is always wearing the same shirt in episodes where he's thrown out.
Will Smith's character name in the show is actually different than in real life. In the show, he is "William" Smith, in real life he's "Willard" Smith. This is referred to when one of Will's girlfriend's father calls him Williard as a joke.
The show was originally canceled by NBC after the fourth season, with the series finale being the episode where Will moves back to Philadelphia. However, fan reaction and letters written to Will Smith and NBC persuaded them to renew the show and it ended up continuing for two more seasons.
The part of Aunt Vivian Banks was portrayed by two different actresses during the series run. 'Janet Hubert-Whitten' portrayed the original Vivian during seasons 1-3, but growing problems between Will Smith, the producers, and Hubert-Whitten caused her to depart in 1994. The producers offered Hubert-Whitten a 12/25 contract for season four, but she declined. Daphne Maxwell Reid replaced her in the role from 1994-1996, seasons 4-6.
May have been the first TV series saved from cancellation by pleas from TV-station managers. The show aired its 1990-1994 episodes in syndication after the fourth season while running the fifth season on network. At the end of that season, NBC wanted to pull the plug because the new episodes were getting a mediocre 8.6 rating. But the reruns were drawing a 7.4, extremely good for an ad-hoc collection of shows you've seen three or four times, and the managers of the local stations thought they might have one of those "phenom" series where people religiously watch their favorite episodes and a lot of them. To avoid over-running the shows they already had (about a hundred, already run three times), the station managers agreed to buy the fifth and sixth seasons at a greatly inflated price (adding 50 more shows to their libraries and helping avoid burning out the audiences) - meaning NBC would NOT lose money by picking up the show after all.
During the fall of 1991-92 season, NBC gained two hit television shows to anchor their Monday night line-up ("Blossom" aired after "The Fresh Prince of Bel-Air"). To gain popularity between the two shows, Will Smith appeared in an episode as himself under the rap persona of The Fresh Prince. Several episodes later, Karyn Parsons showed up in an episode of "Blossom", as Hilary Banks. Parsons also appeared in the Patti LaBelle sitcom, "Out All Night" as her Fresh Prince character.
In the UK, the show was exclusively aired in 1991 on BBC Two up until the Summer 2004, originally in the DEF II programming block. The channel edited some of the episodes so that, like the pilot, the titles would comes before the beginning of the episode; this was indicated by the lack of credits in the first scene.