The Isabella Stewart Gardner Museum is an art museum in Boston, Massachusetts, which houses significant examples of European, Asian, and American art. Its collection includes paintings, sculpture, tapestries, and decorative arts. It was founded by Isabella Stewart Gardner, whose will called for her art collection to be permanently exhibited "for the education and enjoyment of the public forever".

An auxiliary wing, adjacent to the original structure near the Back Bay Fens, was completed in 2012.In 1990, thirteen of the museum's works were stolen; the crime remains unsolved, and the works, valued at an estimated $500 million, have not been recovered. A $10 million reward for information leading to the art's recovery remains in place.

Art theft, sometimes called artnapping, is the stealing of paintings, sculptures, or other forms of visual art from galleries, museums or other public and private locations. Stolen art is often resold or used by criminals as collateral to secure loans. Only a small percentage of stolen art is recovered—an estimated 10%. Many nations operate police squads to investigate art theft and illegal trade in stolen art and antiquities.Some famous art theft cases include the robbery of the Mona Lisa from the Louvre in 1911 by employee Vincenzo Peruggia. Another was theft of The Scream, stolen from the Munch Museum in 2004, but recovered in 2006. The largest-value art theft occurred at the Isabella Stewart Gardner Museum in Boston, when 13 works, worth a combined $500 million were stolen in 1990. The case remains unsolved.