Born in 1935 in Shenyang, China, to Japanese parents, Seiji Ozawa started piano lessons at an early age. After graduating from Seijo Junior High School in Tokyo, he studied conducting under the late Hideo Saito at Toho School of Music, graduating with first prizes in composition and conducting.

In 1959 he won first prize at the International Competition of Orchestra Conductors held in Besançon, France, and was invited to Tanglewood by Charles Münch, then Music Director of the Boston Symphony Orchestra and a judge at the competition. In 1960 Ozawa won the Tanglewood Music Center's highest honor, the Koussevitzky Prize for outstanding student conductor.

While a student of Herbert von Karajan in West Berlin, Ozawa came to the attention of Leonard Bernstein. He was appointed assistant conductor of the New York Philharmonic for the 1961-62 season. He was Music Director of the Chicago Symphony Orchestra's Ravinia Festival for five summers beginning in 1964. Ozawa also took the post of Music Director of the Toronto Symphony Orchestra for four seasons.

Ozawa was Music Director of the San Francisco Symphony from 1970 to 1976, followed by a year as that orchestra's Music Adviser. He first conducted the Boston Symphony Orchestra in Symphony Hall in January, 1968. From 1970 he was designated Artistic Director of the Boston Symphony Orchestra's Tanglewood Festival for four summers. Following a year as the Music Adviser of the orchestra, Seiji Ozawa was named the 13th Music Director of the Boston Symphony Orchestra in 1973.

With the Boston Symphony Orchestra, Ozawa conducted many concerts in Europe, Asia and throughout the United States, strengthening the orchestra's international reputation.
In late April, 2002, Seiji Ozawa conducted performances of Mahler's Symphony No.9 in Boston, bringing to a close a tenure of twenty-nine years as Music Director of the Boston Symphony Orchestra. In fall, 2002, he assumed the post of Music Director of the Vienna State Opera. Preceding this, on January 1, 2002, Seiji Ozawa became the first Japanese conductor in history to appear on the podium for the Vienna Philharmonic's New Year Concert. This concert was broadcast in 65 countries, receiving acclaim from audiences around the world. The live recording was then released with unprecedented speed and has become a phenomenon, rising on the Pop Music chart rankings and hitting record-breaking Classical Music CD sales, receiving a Platinum Disk Award in the Orchestra's home country of Austria, and a Classic of the Year Award at the 16th Nihon Gold Disk Award in Japan.
In March 1979, he and the Orchestra made a historic visit to China, becoming the first American performing ensemble to visit China since the establishment of diplomatic relations.

Ozawa maintains an active international career, appearing regularly with many orchestras including the Berlin Philharmonic, and often leading European and Japan tours with the Vienna Philharmonic. His operatic credits include several appearances receiving great response at the Vienna State Opera, La Scala, Milan, l'Opéra National de Paris, among others. In 1983 he conducted the world premiere of Olivier Messiaen's Saint Francois d'Assise at l'Opéra National de Paris.

In 1984, Seiji Ozawa and Kazuyoshi Akiyama formed an orchestra whose purpose was to perform in commemoration of the late Japanese music educator, Hideo Saito. This orchestra, the Saito Kinen Orchestra, formally embarked on a path to greatness in 1987 that has since become legendary. In 1992, the orchestra became the focus of Ozawa's artistic dream to be Japan's first international music festival: the Saito Kinen Festival Matsumoto. The Festival, which has been held every September since it's commencement in 1992, has drawn the enthusiastic attention of the music world both at home and abroad.

In 1998 Seiji Ozawa and the Saito Kinen Orchestra joined forces with l'Opéra National de Paris to produce Francis Poulenc's Dialogues des Carmélites at the Festival, then mounted the same production at l'Opéra National de Paris in November of 1999. In the same year at the Festival, with director Robert Lepage, Berlioz's Opera, La Damnation de Faust was presented and highly praised. In December 1999 and January of 2000, Seiji Ozawa conducted the Saito Kinen Orchestra in performances of Mahler's Resurrection Symphony in Matsumoto as well as Tokyo to a resoundingly positive response, the energy of which has been captured on a live audio recording. The acclaimed conductor took the Saito Kinen Orchestra to Europe for performance tours in
1989, 1990, 1994, 1997, plus a 1991 tour of both Europe and the United States, and a 2001 tour of the United States. In May 2004, Seiji Ozawa led the Saito Kinen Orchestra on a highly successful European Tour, performing in a total of 6 cities throughout Europe (Valencia, Berlin, Vienna, Paris, London, and Milan).

Seiji Ozawa's activities have earned him France's esteemed honor, Chevalier de la Legion d'Honneur (1998), an Honorary Doctorate from Harvard University (2000), membership in the Académie des Beaux-Arts de l'Institut de France (October 2001), and in November 2001, recognition from Japan for his outstanding cultural contributions to the country. He received the Austrian Cross of Honor for Science and Art, First Class, from Austrian President Thomas Klestil (2002), the Mainichi Art Award and Suntory Music Prize (2003), and in March 2004, received an Honorary Doctorate from the Sorbonne University of France.

2000 marked the beginning of "Seiji Ozawa Ongaku-juku Opera Project," designed as an educational program for young musicians. The first six of its productions, Mozart's Le Nozze di Figaro, Così fan tutte, Don Giovanni, J. Strauss II' s Die Fledermaus, Puccini’s La Bohème and Rossini’s Il Barbiere di Siviglia received popular attention from audiences and critics for the way in which the progress of young musicians was achieved. In addition to these projects, Seiji Ozawa continues to perform on a regular basis with the New Japan Philharmonic, an orchestra with which he has worked closely since its founding, and once a year with the Mito Chamber Orchestra.
Seiji Ozawa conducted two comic operas, L'heure espagnole (Ravel) and Gianni Schicchi (Puccini), in collaboration with l'Opéra National de Paris in April 2003. The production, which was performed in Yokosuka, Kawaguchi and Tokyo, was very successful and delighted the audience. The production was also performed 8 times from March to April 2004 at l'Opéra National de Paris.

(January 2006).