He was born in Hoten (Shenyang), Manchukuo. He studied at the Toho School of Music in Tokyo, graduating in 1959. He then went to Europe for further study. He was taken to the United States of America by Charles Munch for lessons at the Berkshire Music Center (now the Tanglewood Music Center). He won a scholarship to study with Herbert von Karajan and the Berlin Philharmonic Orchestra, and in 1961 he was appointed an assistant conductor of the New York Philharmonic Orchestra by Leonard Bernstein. He was music director of the Toronto Symphony Orchestra from 1965 to 1970, of the San Francisco Symphony Orchestra from 1969 to 1976, and of the Boston Symphony Orchestra from 1973 to 2002. He has been music director of Vienna State Opera since 2002.
Ozawa has also been an advocate of 20th century classical music, giving the premieres of a number of works, including Gyorgy Ligeti's San Francisco Polyphony in 1975 and Olivier Messiaen's opera Saint François d'Assise in 1983.