'Senior storm leader';[1][2] short: Ostuf) was a Nazi Germany paramilitary rank that was used in several Nazi organisations, such as the SA, SS, NSKK and the NSFK.

The rank of Obersturmführer was first created in 1932 as the result of an expansion of the Sturmabteilung (SA) and the need for an additional rank in the officer corps.

[3] An SA-Obersturmführer was typically a junior company commander in charge of fifty to a hundred men.

Within the SS, the rank of Obersturmführer carried a wider range of occupations including staff aide, Gestapo officer, concentration camp supervisor, and Waffen-SS platoon commander.

Within both the SS and SA, the rank of Obersturmführer was considered the equivalent of an Oberleutnant in the German Wehrmacht.