[1] Cyrielle Chatelain comes from a family of left-wing activists – her parents, both special education teachers, support Greenpeace and the anti-nuclear movement.

[7] From 2012 to 2014, she worked as a parliamentary assistant to Éric Alauzet, an ecologist deputy from the Doubs region, and from 2015 to 2018, she was in charge of the housing file in the office of Christophe Ferrari, President of the Grenoble Metropolitan Council.

In September 2022, Bayou withdrew from leadership after accusations of psychological violence from an ex-partner, leaving Chatelain as sole president of the group.

[12] As part of the New Ecological and Social People's Union (NUPES) coalition for the 2022 legislative elections, and still affiliated with The Ecologists (EELV), Cyrielle Chatelain is running in Isère's 2nd constituency, with Alban Rosa, La France Insoumise municipal councilor in Échirolles, as her deputy.

[13] Unknown to the general public at the time, she was chosen unanimously, despite the fact that several better-known personalities, such as Sandrine Rousseau and Delphine Batho, had been shortlisted.

[18][19][20] Under the New Popular Front banner, Cyrielle Chatelain was re-elected in the 2024 legislative elections with 62.07% of the vote against Édouard Robert of the National Rally.