The Boulogne is a river of France.

This river runs in Loire-Atlantique and the Vendée, to throw itself in the Lac of Large-Place. It takes its source in the Vendée, in extreme cases of the communes of the Essarts and of Merlatière, then goes up towards north. It sprinkles in particular the commune of Boulogne, Lucs-on-Boulogne and Rocheservière in the Vendée. Then enters in Loire-Atlantique, crosses Saint-Philbert-of-Large-Place, before throwing itself in the Lac of Large-Place which it feeds.