The Lotsenhaus Stralsund is a listed building in the port of the city of Stralsund in Hafenstraße with the postal address Hafenstraße 50.
The house was built in 1901 as a pilot's watch. The two-storey brick-roofed brick building with up to two meters thick masonry stands on two crossed barrel vaults in a former casemate of the port fortifications. It was built within three months by the Stralsund companies Theichen and Mackenthun & Sohn according to plans by the architect Ernst Dalmer. The semicircular closed east side is windowed, designed like a tower and crowned with a pointed roof. The western entrance side of the building, which stands on a high plinth, shows a high stepped gable with a panel structure. The two single-storey extensions also have panels.
Originally the revetment was green.
The building was extensively renovated from June 2009 to June 2010; it is used as a port authority.
The house is located on the outskirts of the city area recognized by UNESCO as a world cultural heritage site of the “historic old towns of Stralsund and Wismar”. It is entered in the list of architectural monuments in Stralsund with the number 833.