John Fitz Marshall was a painter of animals, landscapes and flower subjects. He was educated in and spent most of his life in Croydon. He is also thought to be the son of John Marshall (exh. Royal Academy 1840-69).

Fitz Marshall exhibited some twenty paintings at the Royal Academy from 1883 to 1903, and a further two in 1913 and 1915. He also exhibited at Suffolk Street, the National Gallery and was elected to the Royal Society of British Artists in 1896.

His dog paintings tend to be pet portraits, which have a soft, atmospheric quality.