Lannoy (; ) is a commune in the Nord department in northern France.
With a land area of only , it is the third-smallest French commune (after Castelmoron-d'Albret and Vaudherland) by surface area. It also has the highest density of population of any commune outside of the ÃÂle-de-France region, slightly greater than that of the city of Lyon.
The de Lannoy family and the Delano family are both named for the town of Lannoy.