Peter Dillon was born in Martinique, the son and namesake of an Irish immigrant. Not much is known of his early life. He claimed to have joined the Royal Navy at one point and to have served at Trafalgar. He left the Royal Navy and made his way to Calcutta as a young man, eventually becoming a trader in the South Seas.
In 1813 he sailed to Fiji as third mate in the Hunter under Captain James Robson to look for sandalwood. While there, tensions between the Europeans and the Fijians escalated into violence; many people on both sides of the conflict lost their lives. Dillon recounted the events of this battle in his Narrative and Successful Result of a Voyage to the South Seas (1829). In it he describes holding out with five other people, including Charles Savage, on a rock that was later called "Dillon's Rock" while native Fijians prepared a cannibal feast at which they devoured Dillon's fallen comrades. Recent scholarship has cast doubt on the veracity of Dillon's account, particularly as it pertains to his supposed eyewitness account of mass cannibalism (see Gananath Obeyesekere's Cannibal Talk).
Discovery of La Pérouse Wrecks
In 1826, Dillon had command of the Elizabeth  and was attempting to get to Fiji when he happened upon Tikopia, one of the Santa Cruz Islands. There he found many of the inhabitants in possession of items of European manufacture such as sword guards, teacups, knives, and glass beads. He learned from the Tikopians that the items had come from two ships wrecked some years before on the neighboring island of Vanikoro.
Dillon was convinced he'd happened on the wreckage of La Boussole and L'Astrolabe, the two French frigates of the La Pérouse expedition. The ships had disappeared in the Pacific after calling at Botany Bay in 1788, and their fate had been a mystery for nearly 40 years.
Dillon sailed to Calcutta to report his discovery and garner support for an exploration of Vanikoro. The British government in India gave him command of a survey vessel, the Research, and in January 1827 Dillon sailed for Vanikoro. After a long and difficult journey, he reached Vanikoro in September 1827. While there he recovered items from the wrecks, including a ship's bell of French make. He also tried to learn more about the fate of the French explorers from the older inhabitants of the island. According to Dillon's account in his Narrative and Successful Result, he learned that both ships had been wrecked on the reefs during a storm, that some of the survivors had built a boat from the wreckage and sailed off in it, and that two survivors had remained on the island but had since died.
Dillon eventually made his way to France, where he met Barthélemy de Lesseps, the only living survivor of the La Pérouse expedition. De Lesseps had served the expedition as a Russian interpreter; he'd left the expedition in Petropavlovsk, Siberia and made his way overland back to Europe. He identified the items brought back by Dillon as items that had been carried on the French ships.
In 1829 Dillon published his Narrative and Successful Result. He also received a knighthood and pension from the French government. Much of the remainder of his life was spent in a disappointing search for greater recognition for his achievements. Although generally not recalled, he was one of the character witnesses called by Sir Fitzroy Kelly in the defense of John Tawell for the poison murder of Sarah Hart in March 1845. By all accounts a passionate and complex individual, Peter Dillon by turns charmed and alienated the people he encountered. He died in Paris on 9 February 1847.
- Davidson, J. W. (James Wightman); Spate, O. H. K. (Oskar Hermann Khristian) (1975), Peter Dillon of Vanikoro : Chevalier of the South Seas, Oxford University Press, ISBN 978-0-19-550457-6
- Dillon, Peter (1829), Narrative and successful result of a voyage in the South Seas performed by order of the government of British India, to ascertain the actual fate of La Pérouse's expedition interspersed with accounts of the religion, manners, customs and cannibal practices of the South Sea islanders, London: Hurst, Chance and Co Volume 1 OL24549379M, Volume 2 OL6944927M
- Obeyesekere, Gananath (2005), Cannibal talk : the man-eating myth and human sacrifice in the South Seas, University of California Press, ISBN 978-0-520-24308-8, especially chapter 7, "Narratives of the Self: Chevalier Peter Dillon's Fijian Cannibal Adventures."
- Guillou, Jean (2000), Peter Dillon, capitaine des mers du sud : le découvreur des restes de La Pérouse, Etrave, ISBN 978-2-909599-49-6
- Calder, J. E. (29 January 1881). "Something about old Colonists". The Mercury (Hobart, Tas.: National Library of Australia). p. 1 Supplement: The Mercury Supplement. Retrieved 2012-01-20.
- Davidson, J. W. (1966). "Dillon, Peter (1788–1847)". Australian Dictionary of Biography. Canberra: Australian National University. Retrieved 20 January 2012.