German submarine U-142 was a Type IID U-boat of Nazi Germany's Kriegsmarine during World War II.

She was launched on 27 July 1940 and commissioned on 4 September 1940 with Oberleutnant zur See Asmus Nicolai Clausen in command.

The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of 700 metric horsepower (510 kW; 690 shp) for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of 410 metric horsepower (300 kW; 400 shp) for use while submerged.

[3] The boat's first patrol commenced with her departure from Gotenhafen, (now Gdynia in modern-day Poland) on 21 June 1941.

Her second foray was also abortive, departing Oxhöft 25 July 1941 and arriving in Stormelö (in southwest Finland) on 9 August.