BP said it discovered oil while drilling in the Gila prospect, located about 300 miles off the coast of New Orleans in the deep waters of the Gulf of Mexico.
BP last announced oil discoveries in the Gulf of Mexico at its Kaskida prospect in 2006 and its Tiber site in 2009.
An accident on the Deepwater Horizon drilling rig, which BP leased from Transocean, lead to a cascading series of failures in 2010 at BP's Macondo well. BP said approximately 2.5 million barrels of oil were spilled over the course of 87 days. Eleven rig workers died in the accident.
Richard Morrison, regional president for BP, said the Gila discovery marks the company's return.
"The Gila discovery is a further sign that momentum is returning to BP's drilling operations and well execution in the Gulf of Mexico," he said in a statement.
BP, which co-owns the Gila prospect with ConocoPhillips, said it would need to conduct further appraisal drilling to determine the exact size of the discovery.