Heinrich Lehmann-Willenbrock (December 11th, 1911 – April 18th, 1986) was a German naval officer, and a submarine commander during WWII. He was among the top ten Aces of the Deep during the Second Battle of the Atlantic against the Allies, in terms of tonnage of merchant ships sunk. He commanded four subs, most notable and succesful of which was his tour commanding the U-96, a Type VII U-boat, which gained large recognition when one of its patrols was documented and publicized by an accompanying war correspondent Lothar-Günther Buchheim. It eventually would be made into a mini series and film called Das Boot, where he was portrayed by Jürgen Prochnow.

Willenbrock joined the Kriegsmarine in April 1931, with the rank of Seekadett , serving on a light cruiser and a sailing school ship before he transferred to the U-Boat Flotilla in April 1939, five months before WWII began. Upon serving as an executive officer on U-8 , he was promoted to Kapitänleutnant and took command of U-5 in December 1939. His first patrol, which lasted fifteen days, was along the coast of Norway during Operation Hartmut . No ships were sunk.

Upon the return of U-5 , Willenbrock was transferred to the newly commisioned U-96, whose crew underwent a three-month training period before put onto active duty. After three patrols under Willenbrock's command, U-96 had sunk 125,580 tons of enemy shipping. The third patrol alone resulted in seven ships sunk, for a total of 49,490 tons. The seventh patrol was the approximate time that Lothar-Günther Buchheim boarded U-96 and documented the boat's successes in his book Das Boot, where Willenbrock was regarded extremely highly. Willenbrock earned all of his medals during his patrols with U-96

Willenbrock left U-96 on March 1943 to be promoted to Korvettenkapitän as the commander of the 9th Flotilla , stationed in Brest. He then left on his final patrol aboard the U-256 . No ships were sunk. The Kriegsmarine notified Willenbrock that Brest was occupied by American forces, and ordered the U-256 to return to Bergen, Norway, where he remained until the end of the war. He returned to Germany in May 1946, salvaging ships in the Rhine river. In 1948, he left Germany aboard his ship, Magellan, with three of his friends to Buenos Aires.

He was decorated in 1974 with the Bundesverdienstkreuz am Bande (Federal Merit Cross on Ribbon). In 1982, Willenbrock accompanied Wolfgang Petersen and the Das Boot cast and crew as an advisor to the film. Afterwards, he returned to his home at Bremen, where he remained until his death.

During his patrols with U-96, Willenbrock was awarded with the Iron Cross 2nd Class, the Iron Cross 1st Class, the U-Boat War Badge , the Knights Cross , and the Knights Cross with Oak Leaves for his achievements. Although he wasn't the greatest among the Aces of the Deep, he is certainly the most well-known of the ten.