Bilingual Ana Charlotiaux worked at the couple's Chateau Miraval estate in the South of France until February 2010 dealing with phone and email enquiries, but she alleges that she was sacked for taking too much sick leave.
Ana, 45, has now filed an unfair dismissal case and is seeking £55,000 in compensation from the couple - who are known for their charity work and raise six children together.
At a hearing, her lawyer Emmanuel Ludot said: "She is not asking for much - just fair compensation for wrongful dismissal.
"This money is a drop in the ocean for these stars. She has nothing against them personally, and says she was always treated well by them, but they did not step in to prevent her being dismissed.
"Mr Brad Pitt, who is also famous for his charity work and adoption of children, should understand that my client should be compensated as soon as possible. We hope they will both be faithful to their reputation for humanitarian causes."
He also added that his client had taken around four-and-half months off over two years because of illness.
The Prud'Hommes tribunal will deliver its verdict on Charlotiaux's unfair dismissal case next February.