Born in Nottingham, Arnesby Brown studied at the Nottingham School of Art. Sir John Arnesby Brown was noted for his treatment of skies and the sympathetic depiction of animals in the countryside. He worked in Norfolk and at St Ives where he was a member of the St Ives Art Club. In 1910 he settled in Chelsea, spending his winters there and his summers at the White House, Haddiscoe, Norfolk.

Arnesby Brown exhibited 139 works at the Royal Academy and was elected a Royal Academician in 1915. He also showed at the RBA, RHA, widely in London galleries, He had a one man exhibition at the Leicester Galleries in 1909 and Norwich Castle Museum in 1935, where a memorial exhibition was also held in 1959. His work is represented in collections including the Tate Gallery.

He was knighted in 1938 and died in Haddiscoe in 1955.