Henri Eugène Augustin Le Sidaner (7 August 1862 – 14 July 1939) was a French painter who was a contemporary of the Post-impressionists. He was known for his paintings of domestic interiors and quiet street scenes, which contained elements of impressionism with the influences of Édouard Manet, Monet, and of the Pointillists discernible in his work. Le Sidaner favoured a subdued use of colour, preferring nuanced greys and opals applied with uneven, dappled brushstrokes to create atmosphere and mysticism. His style was described as Intimism, which is characterized by the portrayal of intimate, private spaces and personal moments.

Le Sidaner’s paintings and pastels were widely collected throughout his career. His seductive views of the gardens he created in the ruins of the medieval fortress at Gerberoy, with their recently vacated tables dappled in sunlight and overhung by roses, have cemented his reputation as a unique artist who does not fit easily into an art movement. He travelled widely throughout France and Europe before settling at Gerberoy in the Picardy countryside from where he painted for over thirty years. Le Sidaner’s works are held in the collections of the Musée d’Orsay in Paris, the Art Institute of Chicago, and the National Gallery of Art in Washington, D.C., among others.