A peace treaty between the Flemish and the French is signed at Athis-sur-Orge.

Flanders is the Dutch-speaking northern portion of Belgium and one of the communities, regions and language areas of Belgium. However, there are several overlapping definitions, including ones related to culture, language, politics, and history, and sometimes involving neighbouring countries. The demonym associated with Flanders is Fleming, while the corresponding adjective is Flemish, which can also refer to the collective of Dutch dialects spoken in that area, or more generally the Belgian variant of Standard Dutch.

The Treaty of Athis-sur-Orge was a peace treaty signed on 23 June 1305 between King Philip IV of France and Robert III of Flanders. The treaty was signed at Athis-sur-Orge after the Battle of Mons-en-Pévèle and concluded the Franco-Flemish War (1297–1305).