Thielbek was a 2,815 GRT cargo steamship that was built in Germany in 1940, sunk in an air raid in 1945, refloated in 1949 and repaired, and was in service until 1974. Lübecker Maschinenbau Gesellschaft in Lübeck built her in 1940 for the Knöhr and Burchard shipping company of Hamburg. In 1961 Knöhr and Burchard sold her to buyers who renamed her Magdalene and registered her in Panama. In 1965 she was renamed Old Warrior. She was scrapped in Yugoslavia in 1974.
Thielbek is notable for having been sunk by RAF aircraft on 3 May 1945, killing 2,750 people aboard. She was at anchor in the Bay of Lübeck with the passenger ships Cap Arcona and the Deutschland, which were sunk in the same air raid. At the time Cap Arcona and Thielbek were crowded with prisoners from the Neuengamme, Stutthof, and Mittelbau-Dora concentration camps.