List of successful U-boats contains lists of the most successful German U-boats in the two World Wars based on total tonnage.
World War I This list contains the 5 most successful German U-boats during the First World War based on total tonnage. Only sunk commercial vessels are included, not military (warships) nor damaged ships.
+ 5 Top-scoring U-boats of World War I Boat Type Commissioned Totaltonnage Shipssunk Patrols Fate Captains Type U 31 3 November 1914 505,121 220 17 Surrendered, 26 November 1918 Waldemar KophamelLothar von Arnauld de la PerièreErnst von VoigtHeino von Heimburg Type U 31 13 January 1915 404,774 149 19 Surrendered, 22 March 1919 Hans KratzschWalter ForstmannHeinrich Metzger Type U 31 15 December 1914 287,811 134 17 Surrendered, 23 February 1919 Max ValentinerWilhelm CanarisHans Heinrich WurmbachClemens Wickel Type U 31 5 October 1914 257,652 119 17 Missing, 9 November 1918 Claus RückerWilhelm CanarisJohannes Klasing Type U 51 22 April 1916 224,314 87 13 Surrendered, 1 December 1918 Hans RoseOtto von Schrader
World War II This list contains the 10 most successful German U-boats during the Second World War based on total tonnage. Both commercial and military vessels (warships) are included but only sunk ships are included, not damaged ships.
+ 10 Top-scoring U-boats of World War II Boat Type Commissioned Totaltonnage Shipssunk Patrols Fate Captains VIIB 22 April 1939 300,537 51 12 Scuttled, 3 May 1945 Herbert SchultzeHans-Rudolf RösingHeinrich Bleichrodt VIIB 18 April 1940 244,658 38 8 Scuttled, 17 March 1941 after depth charging by . Otto Kretschmer IXB 18 April 1940 237,596 45 11 Decommissioned March 1944. Sunk by bombs in Kiel, 15 April 1945. Viktor SchützeWerner Winter IXB 11 June 1940 225,637 48 11 Lost with all hands, 2 April 1943 after depth charging by and . Georg-Wilhelm SchulzJohann Mohr IXB 30 May 1940 222,705 44 12 Decommissioned 17 June 1944. Scuttled in port, 19 August 1944. Refloated and taken into French service as Blaison. Karl-Heinz MoehleReinhard HardegenHorst von Schroeter IXB 8 October 1940 217,786 39 13 Lost with all hands 18 August 1944 after depth charging by a Sunderland of 201 Squadron RAF. Günter HesslerHarald GelhausVolker SimmermacherKarl-Heinz Fritz IX 4 August 1938 202,467 55 11 Scuttled, 8 May 1945 Heinrich SchuchWerner HartmannVictor OehrnAsmus Nicolai ClausenUlrich Folkers IXC 20 March 1940 200,021 33 9 Sunk 6 May 1944 by Grumman F4F Wildcats and Grumman TBF Avengers of , rammed by destroyer escort . Richard ZappFriedrich MarkworthPaul FrerksGerhard Seehausen IXC 11 February 1941 197,998 33 10 Sunk 10 April 1944, depth charges and rockets fired by F4F Wildcats and TBM Avengers of . Karl-Friedrich MertenAlbert LauzemisEkkehard ScherrausGerhard SeehausenAlbert Lauzemis VIIB 17 December 1938 191,919 31 10 Missing with all hands, on or about 7 March 1941 while patrolling south of Iceland between 59 deg and 62 deg north. Reason behind her sinking is still unknown with theories ranging from attacks by corvettes and , mines, mechanical failure, and possibly becoming victim of her own torpedoes. Günther Prien
References uboat.net webpage about the most successful U-Boats of World War I - This list does not include military vessels. uboat.net webpage about the most successful U-Boats of World War II - This list does not include military vessels and is therefore not identical to list above. uboataces.com webpages about the most successful U-Boats of World War II - This list seems to miss U-123 in top 5 list.