Philippe-Pierre Jacques-Yves Arnault Cousteau Jr. (born January 20, 1980) is an American oceanographer and environmental activist, the son of Philippe Cousteau and the grandson of Jacques Cousteau. He has continued the work of his father and grandfather by educating the public about environmental and conservation issues. In 2017, he received an Emmy nomination for hosting the syndicated science series Awesome Planet.

He married his wife, Ashlan Gorse in 2013. She and Philippe co-hosted the Travel Channel show Caribbean Pirate Treasure.

He was born in Santa Monica, California, to Jan Cousteau, the widow of Philippe Cousteau, who was killed in a plane crash six months before the birth. He grew up in France and the United States.