Zélia Césarion graduated from the Sorbonne with a degree in political communications. In 2010 she joined the office of France’s Housing Minister, serving as communications coordinator and later as press secretary. Two years later, she moved to the French National Assembly, acting as Parliamentary Assistant to the former Housing Minister, now representing the département of Marne in the Chamber of Deputies. During the same period, she served as Deputy Secretary General for Communications of the French Association of Parliamentary Aides (AFCP). In May 2017, she became Chief Press Secretary to the French Prime Minister, handling communications and media relations. On 15 October 2020 she joined SNCF Réseau, succeeding Radia Ouarti as Chief of Staff to the Chairman.