HSwMS Najaden is a Swedish Navy training ship launched in 1897, previously preserved as a museum ship in Halmstad and moored on the river Nissan by Halmstad Castle, since July 2014 in Fredrikstad, Norway.

The three-masted, wooden hulled sailing ship was constructed at the Royal Naval Shipyard in Karlskrona in 1897 and served in the Swedish Navy as a sail training ship until 1938.

A brief ceremony led by city council's chairman, Conservative Ann-Charlotte Westlund was held in front of Najaden in central Halmstad.

On Saturday, 5 July 2014, Najaden was towed from Halmstad to its new home port in Fredrikstad, Norway.

[4] The sail training ship af Chapman was a contemporary of Najaden in Swedish Navy service.