Mesdag, Hendrik Willem (1831–1915), Dutch painter. He was the leading marine painter of the Hague School, and his style to some extent returned to 17th-century Dutch traditions. In 1881 Mesdag painted a vast panorama, 120 m (395ft) in circumference, of the fishing village of Scheveningen, which is housed in a building especially designed for this painting in The Hague.

Mesdag was a banker until he was 35, when he took up art and studied under English painter Lawrence Alma-Tadema in Brussels. He later lived at The Hague and was known as a painter and wealthy patron of the arts. He presented to the nation his fine collection, containing many paintings of the Barbizon school, together with a building to house it—Mesdag Museum, The Hague. His simple and realistic marine paintings are found in many Dutch galleries. The Return of the Fishing Boats (The Hague) is characteristic.