Hippolyte Roussel (La Ferté-Macé, 22 March 1824 - Gambier Islands, 22 January 1898) was a French priest and missionary to Polynesia, a member of the Congregation of the Sacred Hearts of Jesus and Mary.
In 1854 he was sent to evangelize in the Tuamotus and Mangareva in the Gambier Islands. He was removed from his post in Mangareva because of his "strident pronouncements", and in 1866 was appointed to lead a new mission to Easter Island, with Eugène Eyraud, who died shortly thereafter. During his stay on Easter Island, he compiled notes on the customs and traditions of the islanders, which he sent to Valparaíso in 1869 and which were published in April and June 1926 in the Annals of the Sacred Hearts of Picpus.
In 1871, after conflict with the manager of the Brander plantation, Jean-Baptiste Dutrou-Bornier, he was forced to leave Easter Island, and took 275 islanders with him, leaving only 230 Rapanui on the island. He went to Rikitea on Mangareva with 168 Rapanui, and led the mission there until his death in 1898. He periodically returned to Easter Island including in 1882-83 to appointed Atamu Tekena as the island's king.