The woman was killed with a knife after contacting authorities and was found by police with her three stab wounds, according to local media.
Shots were heard after the attacker entered the Green Oaks care home, located in Montferrier-sur-Lez, shortly after 9.30pm.
Anti-terror police are still searching for the suspect after he reportedly evaded capture and escaped before authorities arrived at the scene.
One source claimed a caretaker was bound and gagged by the attacker but was able to free herself and contact police after escaping from the home in Montferrier-sur-Lez, a small commune around 10km north of Montpellier.
Located in Montferrier-sur-Lez, the home houses 70 retired missionaries who have worked in Africa, as well as several nuns.
The victim is believed to be a nun who lived at the home.
An official said: “One woman, a resident was assassinated. The security forces have evacuated the residents, about 60, who are safe and sound.”
Tributes to the murdered woman …