Peter III of Portugal (Portuguese Pedro) (July 5, 1717 - May 25, 1786) became King Consort of Portugal on the succession of his wife and niece queen Maria I in 1777, and ruled with her until his death. Peter was the younger son of Dom João V and brother of José I.

Peter married Maria in 1760, at which time she was the heir to the throne then held by his brother José I. They had six children, of whom the eldest surviving son succeeded Maria as João VI on her death in 1816. See Kings of Portugal family tree.

Peter made no attempt to participate in government affairs, spending his time hunting or in religious exercises.