By air. Trondheim Airport Værnes is 32 km east of the city. The airport has frequent flights to Oslo (under an hour) and direct connections to Copenhagen, Amsterdam, and a few other European cities. The Værnes Ekspressen bus runs to the centre every 20 minutes and takes 40 minutes; the train is slightly faster but less frequent.
By train. Trondheim Central Station is on the harbour, a ten-minute walk from the cathedral. The overnight sleeper from Oslo takes about seven hours and is a pleasant way to arrive — book a single cabin if you want to sleep properly. From Bodø in the far north, the Nordland Line is one of Europe's great train journeys, taking nine and a half hours through forests, fjords, and the Arctic Circle.
By boat. The Hurtigruten coastal ferry calls at Trondheim northbound and southbound on its Bergen–Kirkenes run — arriving in the morning, leaving the same evening — so a stopover in Trondheim works neatly on either end of a Hurtigruten leg.