German submarine U-881 was a Type IXC/40 U-boat of Nazi Germany's Kriegsmarine during World War II. The ship was ordered on 2 April 1942, laid down on 7 August 1943, and launched on 4 March 1944. She was commissioned into the Kriegsmarine under the command of Kapitänleutnant Dr. Karl-Heinz Frischke (Crew 36) on 27 May 1944. Initially assigned to the 4th U-boat Flotilla, she was transferred to the 33rd U-boat Flotilla on 1 March 1945.
German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-881 had a displacement of when at the surface and while submerged. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-881 was fitted with six torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one SK C/32 naval gun, 180 rounds, and a Flak M42 as well as two twin C/30 anti-aircraft guns. The boat had a complement of forty-eight.
For her first patrol, U-881 was assigned to operate in US coastal waters with wolfpack Seewolf. During this operation U-881 was depth charged and sunk by the American destroyer escort on 6 May 1945 in one of the last actions in American waters of the Atlantic campaign. She sank at position with the loss of all 54 men on board.