Lannoy (French pronunciation: [lanwa]; Dutch: Lanno) is a commune in the Nord department in northern France.

With a land area of only 0.18 km2 (0.069 sq mi), 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 Île-de-France region, slightly greater than that of the city of Lyon.

The de Lannoy family and the Delano family are both named from the town of Lannoy.

This Nord geographical article is a stub.