Thyssen-Bornemisza Museum

| established = | location = Palace of Villahermosa
Paseo del Prado, 8. Madrid, Spain | collection_size = 1,600 | visitors = 1.052.014 (2017) | founder = Heinrich, Baron Thyssen-Bornemisza de Kászon | director = Guillermo Solana (Artistic Director), Evelio Acevedo (Managing Director) | publictransit = Banco de España | website = }}

The Thyssen-Bornemisza National Museum (, ;.}} named after its founder, Baron Heinrich Thyssen-Bornemisza), or simply the Thyssen, is an art museum in Madrid, Spain, located near the Prado Museum on one of the city's main boulevards. It is known as part of the "Golden Triangle of Art", which also includes the Prado and the Reina Sofía national galleries. The Thyssen-Bornemisza fills the historical gaps in its counterparts' collections: in the Prado's case this includes Italian primitives and works from the English, Dutch and German schools, while in the case of the Reina Sofía it concerns Impressionists, Expressionists, and European and American paintings from the 20th century.

With over 1,600 paintings, it was once the second largest private collection in the world after the British Royal Collection. A competition was held to house the core of the collection in 1987–88 after Baron Thyssen, having unsuccessfully sought permission to enlarge his museum in Lugano (Villa Favorita), searched for a better-suited location elsewhere in Europe.

The museum has achieved international notoriety in recent years by refusing to return a master work by Francisco Pizarro that was stolen by the Nazis during the holocaust. The work is thought to be worth millions of dollars and remains in the museum's collections despite decades of formal requests and legal actions by the family it was stolen from. Provided by Wikipedia