Philippe Pastour de Costebelle (ca. 1661 – October 1717) was a naval officer and Governor of Newfoundland, born Languedoc died Louisbourg.
Costebelle served in the French Navy as early as 1683, and in 1692 served as lieutenant to an infantry company sent to Plaisance, the principal French settlement on Newfoundland. There he was immediately involved in defending the port from English naval assaults in the ongoing King William's War, and embarked on raiding expeditions against English settlements on the island. Costebelle distinguished himself, and was promoted to captain in 1694, and lieutenant in 1695. That year he was ordered to improve the fortifications and establish contact with the English colonists in St. Mary's Bay. In 1696 Costebelle was sent to France, and thus did not participate in Pierre LeMoyne d'Iberville's celebrated and destructive Avalon Peninsula Campaign.
When he returned to Plaisance in 1697 he had hoped to succeed to the governorship, but was instead forced to continue in the role of king's lieutenant under first Joseph de Monic and then Daniel d'Auger de Subercase. Monic was frequently absent from the colony, so Costebelle spent a significant time during Monic's tenure in actual command of the colony. In 1702, while awaiting Subercase's arrival, Costebelle rallied the province's defences against Captain John Leake's raiding expedition that brought Queen Anne's War (the War of the Spanish Succession) to Newfoundland.
Subercase arrived to take command in 1703, and adopted a vigorous strategy against the English. In 1705 he led a raiding expedition against English outposts that sought to repeat d'Iberville's successes in 1696. Costebelle went on the expedition, but was injured in an accident en route and saw no action. Subercase's expedition was partly successful, destroying many English settlements, but he was unable to take St. John's. Subercase was rewarded with the governorship of Acadia, and Costebelle was finally appointed governor of Plaisance in 1706. In June 1708 he was awarded the Order of Saint Louis.