The Liane is a 37 km river in the Pas-de-Calais department in northern France. It rises in Quesques and flows into the English Channel at Boulogne-sur-Mer. Other communes along its length include: Selles, Brunembert, Bournonville, Alincthun, Crémarest, Wirwignes, Questrecques, Samer, Carly, Hesdigneul-lès-Boulogne, Isques, Saint-Léonard, Hesdin-l'Abbé, Condette, Saint-Étienne-au-Mont, and Outreau.