The son of a radical socialist and anti-clerical freethinker, Paul-Elie Ranson studied the decorative arts at the École des Beaux-Arts in Limoges, and moved to Paris in 1886 with his wife France.
After a short period spent at the École des Arts Décoratifs in Paris, he switched to the Académie Julian where he met Paul Sérusier, Maurice Denis, Pierre Bonnard and others.

In 1888 Sérusier returned from Pont-Aven with a small, daring and scandalous panel called Le Talisman. On seeing this, Ranson's artistic direction was revealed to him: he, Paul Sérusier, Maurice Denis, Henri Ibels and Pierre Bonnard formed the Nabis group, later to be joined by Ker-Xavier Roussel, Édouard Vuillard, Georges Lacombe, Jan Verkade and Félix Vallotton. Ranson exhibited with the group continuously from the time of their first exhibition in 1891.

Like Sérusier, Ranson was strongly influenced by the painting of Paul Gauguin – flat blocks of colour, simplified forms, and a palette restricted to a few vivid colours – whilst also having great admiration, like his friend Maurice Denis, for the painters of the Middle Ages. In parallel, under the influence of the sculptor Aristide Maillol, he started to invent designs on cartoons to be used in the production of embroidery.

Beginning in 1895 Ranson was attracted by large-scale decorative projects, in particular those by Siegfried Bing. Gifted with a natural sense for decoration and of the harmony of forms and colours, he designed wall paintings, tapestries, wooden boxes, painted paper, etc.

Very often classed in the group of mysterious and undecipherable artists, Ranson stood out from the other Nabis by his interest in theosophy, spiritualism, magic and occultism. Born with a natural curiosity and lively intelligence constrained by a scathing cynicism, his powers of observation were penetrating. As a real Symbolist, he wished to expand the horizon rather than define it.

His wife France played an important role in Ranson's career. She welcomed, sewed, embroidered and helped the group bring some of their projects to fruition, remaining in the background until 1907, the year she and her husband decided to open the Académie Ranson, an art school that prospered until 1932 under her friendly direction.