St John the Baptist was Rodin's second large bronze figure study. Begun in 1878, the head was exhibited independently in the Paris Salon of 1879, followed by the whole figure in plaster in 1880 (with a cross, later abandoned) and in bronze the following year. It was acquired by the French state in 1884 for the Luxembourg Gardens in Paris. An early model for the figure, lacking the head and arms, was later exhibited as the Walking Man.

To counteract the damning criticism of casting from the live model that greeted his first figure, The Age of Bronze, the figure of St John the Baptist was made slightly over life-size. Rodin did not set out to make a religious subject, but the naturally awkward yet forceful pose of his untrained model, an Italian labourer from the Abruzzi named César Pignatelli (the head was taken from a separate model), suggested to him a raw mystical character appropriate to the Baptist. This bronze, the first work by Rodin to enter an English public collection, was presented to the Museum in 1902 by a committee of the sculptor's supporters who had set up a subscription to acquire one of his pieces for the nation. To acknowledge the successful campaign, Rodin was invited to a celebration at the Café Royal, after which students from the Slade and South Kensington Art Schools pulled Rodin's carriage through the streets of London in homage to the artist. St John the Baptist thus became the official symbol of Rodin's dominant influence on establishment sculpture of the early 20th century. The Museum's collection of Rodin's sculpture was later substantially increased by the gift of 18 works from the artist himself in 1914.