Montpellier edged last year's final game between the same sides, climbing a fifth title for six years with a 15-12 victory.
Montpellier, led by experienced French internationals like Safi N & # 39; Diaye, has had a dominant season unbeaten in the pool stages before being seen from Grenoble and then Bayonne to reach the final in Tarbes.
France's winner Cyrielle Banet scored a double in victory over Bayonne, with fellow three-star Caroline Boujard also on the scoring sheet.
But they face a tough challenge from Toulouse, led by Hermet, the backrower, who also leads France.
Toulouse can also call, like Ian Jason, Camille Imart and Fiona Lecat, all of whom designated Les Bleues during the Women's Six Nations.
Toulouse beat the local rivals Blagnac in the semi-finals and had beaten Rennes last week in the quarters.
Stade Toulousain has never won a French title, but their predecessors Toulouse Fémina Sports won nine titles between 1975 and 1995.