Henri Masson was born in 1907 in Spy, small town near Namur, Belgium. His father died in 1919 when Henri was 12 years old. Shortly afterwards Henri and his mother moved to Brussels. Two years later she decided to immigrate and in 1921 they settled in Ottawa, Canada after she remarried a Canadian soldier.

Henri, then fourteen, enrolled in the St. Jean Baptiste School, administered by the Christian Brothers. Two years later, in 1923 Henri started as an apprentice in a metal-engraving shop decorating jewels and chase metal ornaments, becoming a master engraver in 1932 at the age of twenty-five. In 1929 he married Germaine Saint Dennis and they had three children, Armande (1930), Carl (1937) and Jacques (1939). Not being by nature a bohemian, Masson earned his living as an engraver until 1945, ensuring the security of his family. During these years Masson attended the Ottawa Art Association and the Ottawa Art Club. The visits to the National Gallery where he discovered the work of the Group of Seven had inspired him to develop his own colourful style. For all week he still remains busy silver engraver for a firm of wholesale metalsmiths but on Saturdays and Sundays afternoon Masson would paint rolling hills of Gatineau Valley, north of the Ottawa River.

Masson first exhibition to which he submitted a selection of watercolors, pastels and drawings was in 1933 at the Caveau a group of francophone painters in Ontario, founded in 1932 in Ottawa. His first showing of oil paintings was in 1936 in an exhibition at the Ontario Society of Artists in Toronto. In 1938 Masson had his first solo exposition at the Picture Loan Society followed by another solo exhibition in 1939 at the Caveau selling his first paintings few years later.

In 1941 Henry Masson has become a member of Canadian Group of Painters (CGP) that succeeded Group of Seven. The founding members of the CGP included several former Group of Seven members including Lawren Harris, A.J. Casson, Arthur Lismer, A.Y. Jackson, F.H. Varley and Franklin Carmichael. Same year he also joined the Canadian Society of Painters in Watercolor and the Société des Arts Graphiques.

In 1942 Masson exhibited in Addison Gallery, Massachusetts along with A.Y.Jackson, Philip Surrey, Lawren Harris, Edwin Holgate, David Milne and Goodridge Roberts. In 1944 The National Film Board produced a documentary film which discussed Henri Masson and his art along with Marc-Aurele Fortin, Jean-Paul Lemieux, Alfred Pellan and Andre Bieler. In 1945 he was elected President of the Ottawa branch of the Federation of Canadian Artists with Laurence Hyde as Vice-President.

In 1948 he moved to Kingston and began teaching summer classes at Queen’s University. He taught at Queen’s University Summer School in Kingston from 1948 to 1952. Same year Masson moved back to Ottawa and from 1948 to 1950 he was an instructor of children’s classes at the National Gallery of Canada. In the summer of 1954, he taught at the Banff School of Fine Arts and later at Ashbury. In 1955 he was granted an Honorary Doctor of Laws Degree from Assomption College in Windsor, Ontario. That same year he taught at the Kingsmere Summer Festival along with A.Y. Jackson.

A painting by Henri Masson was acquired by Princesse Alice and King Georges VI in 1941 and one of his work was presented as a gift of Government of Canada to Princess Margaret in 1967. From 1943 to 1957 the National Gallery of Canada has acquired 6 artworks by Henri Masson, for comparison – the Gallery acquired 7 works by Cosgrove and 6 by Borduas during the same period. Henri Masson is represented in the permanent collections of corporations, public galleries, and universities including National Gallery of Canada, Museum of Quebec, The Art Gallery of Ontario, The Winnipeg Art Gallery, The Saskatoon Art Gallery, Edmonton Art Gallery, The Art Gallery of Vancouver.