Ly-Fontaine

{{Use dmy dates|date=August 2023}}

{{Expand French|topic=geo|date=December 2008|Ly-Fontaine}}

{{Infobox French commune

|name = Ly-Fontaine

|commune status = Commune

|image = Ly-Fontaine (Aisne) mairie.JPG

|caption = The town hall of Ly-Fontaine

|image coat of arms =

|arrondissement = Saint-Quentin

|canton = Ribemont

|INSEE = 02446

|postal code = 02440

|mayor = Jérôme Vasseur{{cite web|title=Répertoire national des élus: les maires|url=https://www.data.gouv.fr/fr/datasets/r/2876a346-d50c-4911-934e-19ee07b0e503|website=data.gouv.fr, Plateforme ouverte des données publiques françaises|date=2 December 2020|language=fr}}

|term = 2020–2026

|intercommunality =

|coordinates = {{coord|49.7353|3.3086|format=dms|display=inline,title}}

|elevation m = 90

|elevation min m = 65

|elevation max m = 100

|area km2 = 3.47

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

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

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

}}

Ly-Fontaine ({{IPA|fr|lifɔ̃tɛn}}) is a commune in the Aisne department in Hauts-de-France in northern France.