Soissons enters written history under its Celtic name, later borrowed into Latin, Noviodunum, meaning "new hillfort", which was the capital of the Suessiones.

57), after leaving the Axona (modern Aisne), entered the territory of the Suessiones, and making one day's long march, reached Noviodunum, which was surrounded by a high wall and a broad ditch.

Between June 1728 and July 1729 it hosted the Congress of Soissons an attempt to resolve a long-standing series of disputes between the Kingdom of Great Britain and Spain which had spilled over into the Anglo-Spanish War of 1727–1729.

A statue erected with images of French soldiers killed in action in 1917 is behind the St Peter's Church, next to the Soissons Courthouse.

The nearby Espace Pierres Folles contains a museum, geological trail, and botanical garden.