Nay is a commune in the Manche department in Normandy in north-western France.

The town name is first attested under the forms Nas, Naei, without date.

According to Albert Dauzat, there are two possible etymologies:

• Either *Nadium (fundum) from the Gallic msculine name *Nadius;

• From the Gaulish words novio (‘new’) and *ialo- (‘field, clearing’; cognate to Yale and Yell, Shetland).

The name in local dialect is Nayons.

• Communes of the Manche department