The railway from Bordeaux to Sète is an important French 476-kilometre long railway line, that connects the southwestern port city Bordeaux (on the Bay of Biscay) to the southern port Sète (on the Mediterranean) via Toulouse and Narbonne.

[3] The Bordeaux–Sète railway leaves the Bordeaux-Saint-Jean station in southeastern direction, following the river Garonne upstream on its left bank.

It crosses the river Lot near Aiguillon, and passes through Agen.

At Castelsarrasin the railway leaves the Garonne and runs east towards Montauban on the river Tarn, where it turns sharply southeast, and then south to Toulouse.

At Toulouse the railway leaves the Garonne again, following the small river Hers-Mort in southeastern direction.