Lessay (French pronunciation: [lɛsɛ]) is a commune in the Manche department in north-western France. On 1 January 2016, the former commune of Angoville-sur-Ay was merged into Lessay.

Lessay is a small town in the centre of the Cotentin Peninsula, Normandy.

It was founded as a monastery but a town grew up around it over the years. The 10th-century Lessay Abbey is one of the greatest examples of Romanesque architecture in Normandy. It was largely destroyed by fighting in the town during July–August 1944, but has been rebuilt.

Historical population

Year	Pop.	±% p.a.
1968	1,597	—
1975	1,540	−0.52%
1982	1,561	+0.19%
1990	1,921	+2.63%
1999	1,993	+0.41%
2007	2,287	+1.73%
2012	2,259	−0.25%
2017	2,245	−0.12%
Source: INSEE

The arms of Lessay are blazoned : Sable, a woodsman's axe palewise Or, blade to sinister.

• LORAN-C transmitter Lessay
• La Foire: the Sainte Croix fair of Lessay is a trade fair established in the 11th century in order to develop commercial activity in the village. For three days in the second week of September, 42 acres (170,000 m) of Lessay is transformed into a marketplace, attracting over 400,000 visitors. The fair offers demonstrations of old and new trades, thousands of stalls selling a range of products from household equipment to animals, food, cars and garden and agricultural tools.
• Lessay was the location for the studio for English language commercial radio station Contact 94 which was aimed at the Channel Islands before they had commercial radio of their own. The station launched on 5 September 1988 and closed in 1991.

• Communes of the Manche department