Born in England, Ellis studied at the Royal College of Art under Francis Bacon and Henry Moore. In 1957 he migrated to NZ and took up a teaching position at Elam School of Fine Arts, The University of Auckland. He is known for his acrylic and water-based paintings that often evoke rural and urban landscapes through a combination of figuration and abstraction. He has also worked with print, textiles and objects. He was Lecturer in Design at Elam 1957, later Head of Painting Department until 1994.
