Flamanville (French pronunciation: [flamɑ̃vil]) is a commune in the Manche department in north-western France.

The port of Flamanville, in the northern part of the commune, is known as Diélette.

During the summer a high-speed passenger ferry is operated from there to Alderney and Guernsey by Manche Iles Express.

On its territory is installed the seaside Flamanville Nuclear Power Plant, established there in the 1980s, with two PWR reactors of 1300 MWe each, which were put into operation in 1986 and 1987.

A third reactor (an EPR) came into operation in December 2024 after years of delay and cost overruns.