Mühlendammschleuse, Navigation lock in southwestern Rostock, Germany

The Mühlendammschleuse is a lock in Rostock that controls water flow between two sections of the Warnow River at different elevations. It features dual gates designed to manage a height difference of 26 centimeters between the upper and lower river sections.

Construction of this lock began in September 1885 with operations starting in 1886, making it one of the oldest surviving locks in Mecklenburg-Vorpommern. It was built during a period when river transport was essential for regional commerce and growth.

The lock's name comes from the Mühlendamm, a dam that has separated the Warnow's fresh and brackish water for centuries. Until the 1980s, excursion steamers ran from Rostock to Kessin, Schwaan and Bützow. The lock chamber is now a portage route for carryable boats.

Since 2020 the lock chamber has been filled in and rebuilt as a portage route for boats that can be carried. The site lies southwest of the city centre, where the Mühlendamm still divides the Warnow into Oberwarnow and Unterwarnow. The average difference in water level at the weir is 26 cm.

The lock chamber was filled in around 2020 and rebuilt as a portage route for boats that can be carried. The structure is owned by the federal government, together with the lock grounds and the stretch of the Oberwarnow up to the next railway bridge on the Stralsund–Rostock line.