Baron Willem van Dedem, also styled as Willem, Baron van Dedem, (1929–2015) was a Dutch businessman, art collector, art historian and philanthropist.^[1][2] He donated artworks to the National Gallery in London, the Rijksmuseum and the Mauritshuis.^[1]

After donating five works to the Mauritshuis, he was awarded both the Museum Medal and the Officer's Cross of the Order of Orange-Nassau.^[3]

He was president of the board of The European Fine Art Fair (TEFAF).^[1]

His art collection was catalogued in a 2002 book by Peter C. Sutton. A 2012 supplement by Sutton described fifteen later additions. At various times, the collection included works by Rembrandt, Pieter Claesz and Adriaen Coorte.

van Dedem died on 26 November 2015.^[3] His wife Ronny, who survived him, is an artist. They had lived for many years in London.^[3] His great uncle was the shipping magnate Daniel George van Beuningen.^[1]

Works owned by van Dedem included:

• The Adoration of the Magi (1617), Pieter Brueghel the Younger^[1]
• Christ with the Woman Taken in Adultery (1628), Pieter Brueghel the Younger^[1]
• A Calm Sea with Ships near the Shore (c. 1624/5–79), Jan van de Cappelle^[1]
• Still Life with Tazza (1636), Pieter Claesz^[3]
• Still Life of a Bowl of Wild Strawberries (1696), Adriaen Coorte^[1]
• Still Life with Fruit and Wine Glasses on a Silver Plate, Willem Kalf^[3]
• A Young Woman Seated at a Table, Eating (c. 1657), Gabriel Metsu^[1]
• Brazilian Landscape with a House under Construction, Frans Post^[3]
• Three Singers (Allegory of Hearing) (1624 or 1625), Rembrandt^[4]
• Winter Landscape at Arnhem, Salomon van Ruysdael^[3]
• Peasants Dancing outside a Bohemian Inn, Roelant Savery^[3]
• Interior of a Gothis Protestant Church (1692), Emanuel de Witte^[1]

• Sutton, Peter C. (2002). Dutch & Flemish Paintings: The Collection of Willem Baron Van Dedem. Frances Lincoln Ltd. ISBN 978-0711220102.
• Sutton, Peter C. (2012). Dutch and Flemish Paintings: A supplement, The Collection of Willem Baron van Dedem. Frances Lincoln Ltd.