Badinières is located some 45 km south-east of Lyon and 10 km south of Bourgoin-Jallieu. Access to the commune is by the D1085 road from Bourgoin-Jallieu in the north which passes through the heart of the commune and the village before continuing south to Eclose. Apart from some forest along the eastern border the commune is entirely farmland.
The Agny river forms the north-western border of the commune as it flows north-east to join the Bourbre in Nivolas-Vermelle. The Ruisseau de Barthgolomat rises north of the village and flows north-west to join the Agny on the northern border of the commune.
In 2010 the commune had 606 inhabitants. The evolution of the number of inhabitants is known from the population censuses conducted in the commune since 1861 (after the creation of the commune in 1857). From the 21st century, a census of communes with fewer than 10,000 inhabitants is held every five years, unlike larger communes 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" allows, after a transitional period running from 2004 to 2008, the annual publication of the legal population of the different French administrative districts. For communes with a population greater than 10,000 inhabitants, a sample survey is conducted annually, the entire territory of these communes 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.