Jeremy Stephen Maas (31 August 1928 - 23 January 1997) was an English art dealer and art historian, best known for his expertise in Victorian painting.
Maas was born in Penang, then in British Malaya. His father, Oscar Henry Maas (1884-1957), was the son of a Dutch diplomat, and owned a rubber plantation. His mother, Marjorie Turner Maas (née Pope) (1893-1988), was American.
He was educated at Sherborne School and then undertook National Service. He studied English at Pembroke College, Oxford graduating, with a third-class degree, in 1952.
In 1956 he married Antonia Armstrong Willis, daughter of Canadian writer Anthony Armstrong; she was an equestrian and an artist. Both Maas and his wife were over 6 feet (1.8 m) tall. They had two sons and a daughter.
After employment in advertising and printing, he followed his interest in Victorian painting - sparked by reading William Gaunt's Aesthetic Adventure at university - and moved to work at Bonhams auction house, where he established the watercolour and drawings department.
Maas opened his own retail gallery, the Maas Gallery, in December 1960. The gallery was based in Clifford Street in Mayfair, near Bond Street, London. The gallery specialized in Victorian art - paintings, watercolours, and drawings - which at the time was unfashionable and often difficult to sell. He revived interest in the works of the Pre-Raphaelite Brotherhood, and held the first of a series of commercial exhibitions in December 1961. The gallery also exhibited works by contemporary painters, such as Elinor Bellingham-Smith and John Stanton Ward.