The town is in the Canal Valley (Val Canale) between the Carnic Alps and Karawanks ranges in the north and the Julian Alps in the south. Located at the border with both Austria and Slovenia, Tarvisio and its neighbouring municipalities of Arnoldstein and Kranjska Gora form the tripoint of Romance, Germanic and Slavic Europe. The height west of the town centre marks the watershed between the Slizza creek, a tributary of the Gail River which is part of the Danube basin, and the Fella River, tributary of the Tagliamento discharging into the Adriatic Sea. Tarvisio together with the rest of the Canal Valley was part of Austria until 1919.