Oskar von Miller studied engineering at the Munich Polytechnic and joined the civil service in 1878. Lack of career opportunities and the Electrotechnical Exhibition in Paris in 1891 persuaded him to turn to electrical engineering.
Inspired by this, he organized the first German electrotechnical exhibition and, together with Marcel Deprez, installed a 57-kilometer long transmission line based on direct current. With Emil Rathenau, Miller founded the “Deutsche Edisongesellschaft für angewandte Elektricität” in 1883, which became the “Allgemeine Elektricitäts Gesellschaft” (AEG) in 1887.
In 1890, Miller founded an engineering office, and in 1891 he headed the Electrotechnical Exhibition in Frankfurt am Main and demonstrated three-phase remote transmission over 178 kilometers using the three-phase system developed by Mikhail Osipovich Doliwo-Dobrowolski. From 1918 to 1924, he was project manager for the construction of the Walchensee power plant. Oskar von Miller, together with Carl von Linde and Walter von Dyck, also founded the Deutsches Museum in Munich.