Billy-Berclau (French pronunciation: [bili bɛʁklo]; Picard: Bili-Bérclo) is a commune in the Pas-de-Calais department in the Hauts-de-France region in northern France.

[3] A small town 10 miles (16 km) east of Béthune and 12 miles (19 km) southwest of Lille, at the junction of the D163 and N47 roads.

Light industry and a little farming have replaced the coal mining of the past.

The town was completely destroyed during World War I.

On 27 March 2003, an explosion at the dynamite factory killed four people.