Oberleutnant is a junior officer rank in the militaries of Germany, Czechoslovakia, Switzerland and Austria. In the German Army, it dates from the early 19th century. Translated as "Senior Lieutenant", the rank is typically bestowed upon commissioned officers after five to six years of active duty service.
Oberleutnant is used by both the German Heer and Luftwaffe. The German Navy ("Marine") equivalent is Oberleutnant zur See.
To differentiate between the other services, the naval rank is typically listed as Oberleutnant zur See. In the NATO military comparison system, a German Oberleutnant is the equivalent of a First Lieutenant in the Army/Air Forces of Allied nations, a Lieutenant Junior Grade in the United States Navy, and a Sub-Lieutenant in the British Royal Navy. In the Austro-Hungarian Imperial and Royal Navy this rank was called k.u.k. Fregattenleutnant.
During World War II, the Waffen-SS equivalent of Oberleutnant was known as Obersturmführer.