The commune is located 4 km south-west of Belley and 30 km north-west of Chambery. It is traversed by the Tour du Bugey trail. It lies in the Appellation d'origine contrôlée (AOC) zone for wine from Bugey with the label "Roussette du Bugey-Arbignieu".
The commune can be accessed on the D69 from Belley in the north-east which continues west to Colomieu. The D100 road also branches from the D49 at the northern edge of the commune and goes south along the eastern side of the commune joining the D10 which passes through the commune from the D992 in the east through the hamlet of Peyzieu then south-west to Saint-Bois. There are three hamlets in the commune other than Arbignieu: Thoys, Slignieu, and Peyzieu. The commune is approximately half farmland and half forest with most of the forest along the western border.
The Furans river forms the eastern border of the commune and then flows east to join the Rhone. The Ruisseau d'Armaille flows from west to east across the commune into the Furans.
In 2010 the commune had 480 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]
^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.