Mikhail Dolivo-Dobrovolsky, Polish-Russian engineer, electrician, and inventor (d. 1919)
Mikhail Osipovich Dolivo-Dobrovolsky (Russian: Михаи́л О́сипович Доли́во-Доброво́льский; German: Michail von Dolivo-Dobrowolsky or Michail Ossipowitsch Doliwo-Dobrowolski; 2 January [O.S. 21 December 1861] 1862 – 15 November [O.S. 3 November] 1919) was a Russian Empire-born engineer, electrician, and inventor active in the German Empire and also in Switzerland.

After studying in Germany and while working in Berlin for Allgemeine Elektricitäts-Gesellschaft (AEG), he became one of the founders (the others were Nikola Tesla, Galileo Ferraris and Jonas Wenström) of polyphase electrical systems, developing the three-phase electrical generator and a three-phase electrical motor (1888) and studying star and delta connections. The triumph of the three-phase system was displayed in Europe at the International Electro-Technical Exhibition of 1891, where Dolivo-Dobrovolsky used this system to transmit electric power at the distance of 176 km with 75% efficiency. In 1891 he also created a three-phase transformer and short-circuited (squirrel-cage) induction motor. He designed the world's first three-phase hydroelectric power plant in 1891.