What Would Jesus Buy? is a 2007 documentary film produced by Morgan Spurlock and directed by Rob VanAlkemade. The title is a take-off on the phrase, "what would Jesus do?". The film debuted on the festival circuit on March 11, 2007, at the South By Southwest (SXSW) conference in Austin, Texas. It went into general U.S. release on November 16, 2007.

The film follows the exploits of the satirical group Reverend Billy and the Church of Stop Shopping. Although founded as a performance collective rather than an actual religious organization, members of the group express spiritual viewpoints against excessive consumerism and materialism, particularly in the context of Christmas. The aforementioned Reverend Billy, played by social activist Bill Talen, is intended by its non-Christian performer not as parody but as a living example of past radical preachers.