At the beginning of his artistic career, he served as an art restorer for national museums, notably the Louvre. His creative period extended from 1920 to 1970, interrupted by the German occupation between 1941 and 1945.
The colors and cheerfulness of Raoul Dufy's paintings deeply inspired him. Saint-Clair was also interested in the pictorial style of Eugène Boudin and studied his work in depth. In Honfleur, he spent some time working in a studio with the artists André Hambourg, Fernand Herbo, and Jacques Bouyssou. His favorite subjects were his family, loved ones, beach scenes, vacations, and everyday attitudes, drawn with a sure hand. Henry Saint-Clair immortalized vibrantly colored family beach scenes along the Normandy coast, particularly in Deauville, Honfleur, and Trouville.
Oil on cardboard, the artist's preferred technique, defines his unique style of painting. He paints his figures with tenderness and humor, and his lines and colors focus on the essentials. His paintings exude a deep emotion, a sense of life and happiness, as if time had stood still.