Marcella Smith was born in East Molesey, Surrey. Studied at Corcoran School of Art in Washington, USA, at the School of Design in Philadelphia and in Paris. Was a member of RBA, SWA of which she was a vice-president; Society of Artists in St. Ives in Cornwall.
She first came to St Ives in 1914, her initial success at RA in 1916 being St Ives Harbour. Concentrated on landscapes and townscapes in early years, and painted from 3 Porthmeor Studios by 1920. Moved to London 1921 to live with Dorothea SHARP in Maida Vale, but maintained her St Ives studio. She was invited to contribute a painting to Queen Mary's Doll House (1922).
She lived in St Ives with Dorothea SHARP during WWII.
Lived for many years in St. Ives and acted as a curator for Lanham's Art Gallery in the High Street. Exhibited at Royal Academy and New English Arts Club.