The Trollfjord (Trollfjorden) is a 2 km long sidearm of the Raftsund between the Norwegian archipelagos of Lofoten and Vesterålen but administratively located in the municipality of Hadsel , which is a municipality in Vesterålen. With its narrow entrance and steep-sided mountains, Trollfjord cuts westwards from the Raftsundet strait. The name is derived from troll, a figure from Norse mythology.

The mouth of the Trollfjord where it joins the Raftsund is only 100 meters wide. The fjord widens to a maximum width of 800 meters. The mountains surrounding Trollfjord are between 600 to 1100 metres high. It is surrounded by Trolltindan (1084 meter) in the south and Blåfjell (998 meter) and hohe Litlkorsnestinden (980 meter) in the north. The Trollfjord is 72 metres at its deepest point.

Trollfjordslaget (The Battle at Trollfjord) by Gunnar Berg
The Hurtigruten ferries take a small detour into Trollfjord on the way from Bergen to Kirkenes. It is also popular with other cruise ferries.

Until 1960 there was a waterfall at the end of Trollfjord which is now redirected to produce hydroelectricity.

The Battle of Trollfjord (Trollfjordslaget) was fought in 1890 between the first industrial, steam-driven fishing ships and teams of traditional open-boat fishermen over access to the fjord. Johan Bojer described the battle in his 1921 novel The last of the Vikings (Den siste Viking).

A painting by Gunnar Berg, Trollfjordslaget depicts The Battle at Trollfjord. The painting is currently located in the Art Galleri Gunnar Berg on the island Svinøya in Svolvær town.