He starts making drawings before he is ten years old. Eventually, he goes into painting. In 1946, he holds his first exhibition presented along with the drawings of the children he is teaching to . The following year, he publishes "Plaidoyer pour l'Enfant". (Plea in favour of children).
In 1951, he wins the first prize for modern painting at the Spring Exhibition of the Fine Arts Museum of Montreal. He previouly held an exhibition at The Agnès Lefort Gallery. He also participated in a collective exhibition of young artists in Europe and to the Sao Paulo Biennial.
Bellefleur's exhibitions multiply not only in Montreal but also elsewhere in Quebec and in Ontario. But it is in 1968 that full consecration fo his talent takes place: the National Art Gallery holds an important retrospective fo Bellefleur's works first in Ottawa and then in London, Ontario and finally in Montreal. Bellefleur is awarded a second scholarship by the Arts Council of Canada.
In 1988, one of the most famous art writers in Quebec, Mr Guy Robert, publishes in both french and english a major book on the life, the carreer and the work of Bellefleur. This book contains unpublished writings by Bellefleur, great pictures of the artist and his family as well as numerous reproductions of the artis's works from the various periods of his career: drawings,gouaches, etching, lithographs and oil. This book is published by Éditions Iconia and is entitled BELLEFLEUR.
At ninety years old, Léon Bellefleur still has a great enthusiasm and a profound passion for painting. He continues his work. Léon Bellefleur has been a man of great generosity and of great loyalty to people around him, family and friends. He never preoccupied himself with making money, getting honours or reaching celebrity. Humble and truthful, he always believed and said that his work would move along its own course. And he won. Without having compromised on the basic principles of integrity, generosity and respect for others.Léon Bellefleur is certainly one the great canadian painters of the second half of the twentieth century. And a great human being."(clarencegagnon.com)