Paul César Helleu (17 December 1859 – 23 March 1927) was a French oil painter, pastel artist, drypoint etcher, and designer, best known for his numerous portraits of beautiful society women of the Belle Époque.

Helleu attended the Second Impressionist Exhibition in the same year, and made his first acquaintances with John Singer Sargent, James McNeill Whistler, and Claude Monet.

Following graduation, Helleu took a job with the firm Théodore Deck Ceramique Française hand-painting fine decorative plates.

His introduction to James Jacques Tissot, an accomplished society painter from France who made his career in England, proved a revelation.

In Tissot, Helleu saw, for the first time, the possibilities of drypoint etching with a diamond point stylus directly on a copper plate.

The show was installed in a Paris apartment at 1 rue Laffitte, which ran concurrently with the official Salon that year to make a statement.

In 1886, Helleu befriended Robert de Montesquiou, the poet and aesthete, who bought six of his drypoints to add to his large print collection.

His subjects included the Duchess of Marlborough, the Marchesa Casati, Belle da Costa Greene, Jeanne de Montagnac, Louise Chéruit, and Helena Rubinstein.

Looking for new inspiration, Helleu began a series of paintings and color prints of cathedrals and stained glass windows in 1893, followed by flower studies and landscapes of parks in Versailles.

Ships, harbor views, life at port in Deauville, and women in their fashionable seaside attire became subjects for many vivid and spirited works.

On his second trip to the United States in 1912, Helleu was awarded the commission to design the ceiling decoration in New York City's Grand Central Terminal.