The court in Bobigny outside Paris also ordered Air France-KLM CEO Jean-Cyril Spinetta to pay a €15,000 fine in the case, which centred on employee contracts between 2006 and 2008.
The court separately last month imposed the same fines on CityJet itself and its deputy CEO Michael Collins.
The court ruled that Dublin-based CityJet, bought by Air France in 2000, had violated French law by paying its employees under Irish contracts despite most of them being hired in France, living in France and working mainly out of Paris airports.
Taxes on the employees' salaries were also paid to Ireland. After a complaint from French labour inspectors, the employees at the low-cost airline were put under French contracts in December 2008.
The court on Tuesday also ordered Air France and Spinetta to pay €2,000 in damages and interest to each of the 21 employees who brought the suit against the company.