List of successful U-boats contains lists of the most successful German U-boats in the two World Wars based on total tonnage.
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.
|SM U-35||Type U 31||3 November 1914||505,121||220||17||Surrendered, 26 November 1918||Waldemar Kophamel|
Lothar von Arnauld de la Perière
Ernst von Voigt
Heino von Heimburg
|SM U-39||Type U 31||13 January 1915||404,774||149||19||Surrendered, 22 March 1919||Hans Kratzsch|
|SM U-38||Type U 31||15 December 1914||287,811||134||17||Surrendered, 23 February 1919||Max Valentiner|
Hans Heinrich Wurmbach
|SM U-34||Type U 31||5 October 1914||257,652||119||17||Missing, 9 November 1918||Claus Rücker|
|SM U-53||Type U 51||22 April 1916||224,314||87||13||Surrendered, 1 December 1918||Hans Rose|
Otto von Schrader
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.
|U-48||VIIB||22 April 1939||300,537||51||12||Scuttled, 3 May 1945||Herbert Schultze|
|U-99||VIIB||18 April 1940||244,658||38||8||Scuttled, 17 March 1941 after depth charging by HMS Walker.||Otto Kretschmer|
|U-103||IXB||18 April 1940||237,596||45||11||Decommissioned March 1944. Sunk by bombs in Kiel, 15 April 1945.||Viktor Schütze|
|U-124||IXB||11 June 1940||225,637||48||11||Lost with all hands, 2 April 1943 after depth charging by HMS Stonecrop and HMS Black Swan.||Georg-Wilhelm Schulz|
|U-123||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 Moehle|
Horst von Schroeter
|U-107||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 Hessler|
|U-37||IX||4 August 1938||202,467||55||11||Scuttled, 8 May 1945||Heinrich Schuch|
Asmus Nicolai Clausen
|U-66||IXC||20 March 1940||200,021||33||9||Sunk 6 May 1944 by Grumman F4F Wildcats and Grumman TBF Avengers of USS Block Island, rammed by destroyer escort USS Buckley.||Richard Zapp|
|U-68||IXC||11 February 1941||197,998||33||10||Sunk 10 April 1944, depth charges and rockets fired by F4F Wildcats and TBM Avengers of USS Guadalcanal.||Karl-Friedrich Merten|
|U-47||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 HMS Camellia and HMS Arbutus, mines, mechanical failure, and possibly becoming victim of her own torpedoes.