Paul-César Helleu was a French painter and engraver, born in Vannes on 17 December 1859, and died in Paris (7th district) on 23 March 1927.

He inspired Marcel Proust to create the character of the painter Elstir in À la recherche du temps perdu.

The "Helleu style", which characterises elegance or refinement and feminine grace, was extremely successful in Paris as well as in London and New York, where he travelled from 1902 onwards. In 1912, he was commissioned to decorate the ceiling of the Grand Central Terminal in New York, on the theme of the signs of the Zodiac: a starry vault, crossed by a zodiac with golden signs and a silver milky way.