The Langfjorden is a fjord in Møre og Romsdal county, Norway.

The fjord then continues to the east to the village of Eidsvåg in Molde Municipality.

Just before 8:00 p.m. on 22 February 1756, a landslide with a volume of 12,000,000 to 15,000,000 cubic metres (16,000,000 to 20,000,000 cubic yards) — the largest known landslide in Norway in historic time — traveled at high speed from a height of 400 metres (1,312 ft) on the side of the mountain Tjellafjellet into the Langfjorden about 1 kilometre (0.6 mi) west of Tjelle and between Tjelle and Gramsgrø.

The slide generated three megatsunamis in the Langfjorden and the Eresfjorden with heights of 40 to 50 metres (131 to 164 ft).

Damaging waves struck as far away as Veøy, 25 kilometres (16 mi) from the landslide — where they washed inland 20 metres (66 ft) above normal flood levels — and Gjermundnes, 40 kilometres (25 mi) from the slide.