Which city is the Banks family mansion located in on The Fresh Prince of Bel-Air?

The Banks family mansion in The Fresh Prince of Bel-Air is located in Bel-Air, Los Angeles.

The setting creates the central social contrast of the series. Will comes from West Philadelphia and moves to the affluent Los Angeles neighborhood of Bel-Air, where his relatives live in a large mansion. Much of the sitcom's action takes place inside that home.

Bel-Air is an actual neighborhood in the Los Angeles area, known for large estates and an affluent reputation. The show uses that real setting while presenting a fictional Banks household and fictional family events. The location is therefore different from the city named in Will's backstory.

Beverly Hills is another famous affluent Los Angeles-area community, which is why it is a plausible mix-up, but it is not the Banks family's stated neighborhood. West Philadelphia is Will's original home, not the location of the mansion.