Born in Milan to an English father and Belgian mother, Marcel Jefferys was an impressionist painter of still life, genre scenes and landscapes in oil and watercolour. Although largely self-taught as an artist, he did receive private lessons from Henriette Ronner-Knip in Brussels (where his family had moved to in 1880). His early influences were Cezanne, Monet and Pissarro, as well as fellow Belgians Emile Claus and James Ensor, the latter whom was particularly important to his artistic evolution.
Jefferys travelled widely in Europe, and visited the USA in 1893, before moving to Chelsea, London during the First World War. The death of his son during the war was a blow from which he never recovered and led to a darkening of his palette. His work from this point consisted largely of views of the river Thames shrouded in fog, showing the influence of Monet and Whistler..
Although turned down as a member of Les XX he did belong to the movements La Libre Esthetique, Les Independants, Art of Today, Pour L’Art and Société Artistique et Littéraire and he participated in numerous national and international exhibitions
His work is held in museums in Paris, Brussels, Ghent and Liege.