Trysfjorden is a fjord located in the municipality of Kristiansand in Agder county, Norway.

[1] The European route E39 highway runs along the inner part of the fjord, just west of the village of Lohne.

The deepest parts of the fjord reach about 85 metres (279 ft) deep.

In the mud at the bottom, scientists have discovered crustaceans that they believe are indigenous to the bay.

Near the villages of Trysnes and Lastad lies the island of Lastadholmen which in recent years has had the largest colony of terns in Southern Norway.