In the largest art theft in US history, 12 paintings, collectively worth around $500 million, are stolen from the Isabella Stewart Gardner Museum in Boston.

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.

In the early hours of March 18, 1990, 13 works of art were stolen from the Isabella Stewart Gardner Museum in Boston. Security guards admitted two men posing as policemen responding to a disturbance call, and the thieves bound the guards and looted the museum over the next hour. The case is unsolved; no arrests have been made, and no works have been recovered. The stolen works have been valued at hundreds of millions of dollars by the FBI and art dealers. The museum offers a $10 million reward for information leading to the art's recovery, the largest bounty ever offered by a private institution.

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."

Boston is the capital and most populous city of the U.S. state of Massachusetts. The city serves as the cultural and financial center of New England, a region of the Northeastern United States. It has an area of 48.4 sq mi (125 km²) and a population of 675,647 as of the 2020 census, making it the third-largest city in the Northeastern United States after New York City and Philadelphia. The larger Greater Boston metropolitan statistical area has a population of 4.9 million as of 2023, making it the largest metropolitan area in New England and the eleventh-largest in the United States.