Berthen (French pronunciation: [bɛʁtɛn]; in Dutch: Berten), located at the foot of Mont des Cats, is a commune in the Nord department in northern France.

It is 2 km (1.2 mi) from the Belgian border, and 5 km (3.1 mi) north of Bailleul.

Historical population

Year	Pop.	±% p.a.
1968	426	—
1975	406	−0.68%
1982	439	+1.12%
1990	464	+0.69%
1999	517	+1.21%
2009	501	−0.31%
2014	522	+0.82%
2020	577	+1.68%
Source: INSEE

The ancient church dated from 1589. The church and village was destroyed on 28 May 1940 by German bombing.

The new church was begun in 1961 to the plans of the architect E.-M. Thibault and consecrated 12 July 1964. The new church retains the profile of the old. Claude Blanchet's windows show the Passion.

The arms of Berthen are blazoned : Or, a bordure azure, and on an inescutcheon argent, a lion gules armed, langued and crowned Or, within a bordure azure. (Caëstre and Berthen use the same arms.)

• Communes of the Nord department