The world's first woman President was Marma Estela 'Isabel' Martinez Cartas de Peron of Argentina. She was the President of Argentina from 1974 to 1976.
After her husband President Juan Peron died in office, Isabel served as President from July 1, 1974 to March 24, 1976.
The world's first elected woman President was Vigdis Finnbogadsttir of Iceland, between 1980 and 1996.