Théo (Théophile) van Rysselberghe (23 November 1862 – 14 December 1926) was a Belgian neo-impressionist painter, who played a pivotal role in the European art scene at the turn of the century.
He discovered the pointillist technique when he saw Georges Seurat's La Grande Jatte at the eighth impressionist exhibition in Paris in 1886. This shook him up completely. Together with Henry Van de Velde, Georges Lemmen, Xavier Mellery, Willy Schlobach and Alfred William Finch and Anna Boch he "imported" this style to Belgium. Seurat was invited to the next salon of Les XX in Brussels in 1887. But there his La Grande Jatte was heavily criticized by the art critics as "incomprehensible gibberish applied to the noble art of painting".
Théo van Rysselberghe abandoned realism and became an adept of pointillism. This brought him sometimes in heavy conflict with James Ensor. In 1887 van Rysselberghe already experimented with this style, as can be seen in his Madame Oscar Ghysbrecht (1887) and Madame Edmond Picard (1887). While staying in summer 1887 a few weeks with Eugène Boch (brother of Anna Boch) in Batignolles, near Paris, he met several painters from the Parisian scene such as Sisley, Signac, Degas and especially Henri de Toulouse-Lautrec. He appreciated especially the talent of Toulouse-Lautrec. His portrait Pierre-Marie Olin (1887) closely resembles the style of Toulouse-Lautrec of that time. He managed to invite several of them, including Signac, Forain, and Toulouse-Lautrec to the next exhibition of Les XX.