The 3rd U-boat Flotilla (German 3. Unterseebootsflottille), also known as Lohs Flotilla, was the third operational U-boat unit in the German Kriegsmarine. Founded on 4 October 1937 under the command of Kapitänleutnant Hans Eckermann, it was named in honour of Oberleutnant zur See Johannes Lohs. Lohs, a U-boat commander during World War I, died on 14 August 1918 after his submarine UB-57 was sunk by a mine.