Michael Gielen was born in 1927 in Dresden and emigrated to Argentina in 1940 with his family. He began his career as singing coach at the Teatro Colón. In 1949, while still in Buenos Aires, he performed all of Arnold Schönberg´s compositions for piano. 1950 he became a singing coach and conductor at the Vienna State Opera.

In 1960 Michael Gielen was appointed musical director of the Royal Opera in Stockholm, and in 1968 was named chief conductor of the Belgian National Orchestra. Later on, he became chief conductor of the Dutch Opera up until 1975. He has worked with the majority of Europe´s major orchestras as a visiting conductor; from 1978 – 1981 he was chief guest conductor of the BBC Symphony Orchestra in London. Foreign tours have taken him to Australia, Japan and the United States, where he assumed the position of musical director of the Cincinnati Symphony Orchestra at the beginning of the 1980/81 season. From 1977 to 1987 Michael Gielen was director of the Frankfurt Opera and general musical director for the city of Frankfurt.
From 1987 to 1995 he ran the class for conductors at the "Mozarteum" in Salzburg.

With the beginning of the 1986/87 season Michael Gielen assumed the position of chief conductor of the SWR Symphony Orchestra Baden-Baden und Freiburg. Within his repertoire spreading from Bach to contemporary music he focused on cyclic performances and recordings of Beethoven´s and Mahler´s Symphonies. Under his direction the orchestra gained international reputation and was invited at the Salzburg Festival, Festival d´Automne in Paris, Berliner Festwochen, Edinburgh International Festival, Carnegie Hall New York and at many other important festivals and concert halls. Since the beginning of the 1999/2000 season he is Permanent Guest Conductor of the SWR Symphony Orchestra.