Mr. Brainwash is a name used by French-born, Los Angeles-based filmmaker and street artist Thierry Guetta. According to the 2010 Banksy-directed film Exit Through the Gift Shop, Guetta was a proprietor of a used clothing store, where he began as a security guard, and amateur videographer who was first introduced to street art by his cousin, the street artist Invader, and who filmed street artists through the 2000s and "evolved" into an artist in his own right in a matter of weeks after an off-hand suggestion from Banksy.

A number of critics have observed that his works strongly emulate the styles and concepts of Banksy, and have speculated that Guetta is an elaborate prank staged by Banksy, who may have created the works himself. Banksy insists on his official website, however, that Exit Through the Gift Shop is authentic and that Guetta is not part of a prank.