Monchy-Lagache

{{Infobox French commune

|name = Monchy-Lagache

|commune status = Commune

|image = L'Omignon en mai 2010 onze.JPG

|caption = The church in Monchy-Lagache

|image coat of arms = Blason fam fr Monchy.svg

|arrondissement = Péronne

|canton = Ham

|INSEE = 80555

|postal code = 80200

|mayor = Jacques Pinchon{{cite web|title=Répertoire national des élus: les maires|url=https://www.data.gouv.fr/fr/datasets/r/2876a346-d50c-4911-934e-19ee07b0e503|publisher=data.gouv.fr, Plateforme ouverte des données publiques françaises|date=13 September 2022|language=fr}}

|term = 2020–2026

|intercommunality = CC Est de la Somme

|coordinates = {{coord|49.8525|3.0453|format=dms|display=inline,title}}

|elevation m = 74

|elevation min m = 57

|elevation max m = 95

|area km2 = 15.44

|population = {{France metadata Wikidata|population_total}}

|population date = {{France metadata Wikidata|population_as_of}}

|population footnotes = {{France metadata Wikidata|population_footnotes}}

}}

Monchy-Lagache ({{IPA|fr|mɔ̃ʃi laɡaʃ}}) is a commune in the Somme department in Hauts-de-France in northern France.