Athies-sous-Laon is located 3 km east of Laon and 15 km west of Sissonne. It can be accessed by the D977 from Laon which continues east to Gizy. The Autoroute des Anglais (A26, E17) traverses the commune from north to south-east but there is no exit in the commune. There is also a railway line going east from Laon with a station in the commune north-east of the town. The town area of Athies-sous-Laon is quite large but is separated from Laon by farmland. There is the remains of part of a disused airbase in the north of the commune but most of the rest of the commune is farmland with a small area of forest near the town.
The Ru du Barentons stream flows from the north where it forms part of the northern border of the commune and continues south-east through the town then west to join the Marais Canal.
In 2012 the commune had 2,624 inhabitants. The evolution of the number of inhabitants is known through the population censuses conducted in the town since 1793. From the 21st century, a census of municipalities with fewer than 10,000 inhabitants is held every five years, unlike larger towns that have a sample survey every year.[Note 1]
Sub-Lieutenant César Méléra of the Colonial Infantry was born in Athies-sous-Laon on 14 July 1884, mobilized on 2 August 1914, fought at the Yser, in Artois, the Champagne, and in Verdun. He was severely wounded in Verdun on 18 August 1916, three times mentioned in dispatches, Chevalier of the Legion of Honour. He died for France struck by a bullet to the heart at Brin (Lorraine) on 25 October 1918. He was the Author of the book Verdun (June–July 1916) the Mountain of Reims (May–June 1918), Editions de La Lucarne, 1925 (French). His name appears in the Panthéon among dead writers of the Field of Honour during the 1914-1918 war.
^At the beginning of the 21st century, the methods of identification have been modified by law No. 2002-276 of 27 February 2002 , the so-called "law of local democracy" and in particular Title V "census operations" which allow, after a transitional period running from 2004 to 2008, the annual publication of the legal population of the different French administrative districts. For municipalities with a population greater than 10,000 inhabitants, a sample survey is conducted annually, the entire territory of these municipalities is taken into account at the end of the period of five years. The first "legal population" after 1999 under this new law came into force in 1 January 2009 and was based on the census of 2006.