The Hers-Mort (the "Dead Hers", as opposed to the faster-flowing Hers-Vif, or "Live Hers") is a long river in southern France, a right-bank tributary of the Garonne. Its average flow rate is . The Hers-Mort rises in the Lauragais region, near the village Fonters-du-Razès, in the Aude department. It flows northwest through the following departments and towns:

• Aude: Payra-sur-l'Hers, Salles-sur-l'Hers
• Haute-Garonne: Villefranche-de-Lauragais, Baziège, Toulouse, Saint-Jory

The Hers-Mort (the "Dead Hers", as opposed to the faster-flowing Hers-Vif, or "Live Hers") is a long river in southern France, a right-bank tributary of the Garonne. Its average flow rate is . The Hers-Mort rises in the Lauragais region, near the village Fonters-du-Razès, in the Aude department. It flows northwest through the following departments and towns:

• Aude: Payra-sur-l'Hers, Salles-sur-l'Hers
• Haute-Garonne: Villefranche-de-Lauragais, Baziège, Toulouse, Saint-Jory