Ercheu (French pronunciation: [ɛʁʃø]; Picard: Èrchu ) is a commune in the Somme department in Hauts-de-France in northern France.

Diverting from the Latin word " Arx-Arcis ", strengthened place: The name of the municipality is unchanged since 1764.

Ercheu lies on the D15 and D168 junction, and is around 7.5 kilometres (5 mi) south of Nesle and 13 kilometres (8 mi) east of Roye, stretching from the Canal du Nord to the Petit Ingon, which originates in the neighbouring municipality of Libermont, in the Département of Oise.

The castle-like Ferme Lannoy was a monastery named Notre Dame ('Our Lady') in the 14th century.

[1] Ercheu is part of the communauté de communes du Grand Roye since January 1, 2012.