Clairmarais (French pronunciation: [klɛʁmaʁɛ]; West Flemish: Klaarmares) is a commune in the Pas-de-Calais department in the Hauts-de-France region of France.

[3] 2 miles (3 km) northeast of Saint-Omer.

The Neufosse Canal, which connects the rivers Aa and Lys, passes by the commune.

During World War I, the Royal Flying Corps, and later Royal Air Force, operated from Clairmarais aerodrome.

[5] This Pas-de-Calais geographical article is a stub.