Julius Rudel was one of the best-known American conductors and musical administrators mainly associated with operatic performances. As a child, he was deeply attracted to music, regularly attended the Vienna Philharmonic concerts and saw some of the great conductors of the age, including Knappertsbusch, Furtwängler, and Walter. He began his formal studies at the Academy of Music in Vienna. At the time of the Nazi occupation of Austria, he left the country and completed his musical studies at Mannes School of Music in New York, graduating in 1943. He became a naturalized U.S. citizen in 1944.

After graduation, he was hired on the musical staff of the New York City Opera, where he helped prepare performances. His debut as a professional conductor was with the NYCO on November 25, 1944. He remained with the NYCO for 35 years, becoming its principal conductor and general director in 1957. One of his most astute decisions was in engaging soprano Beverly Sills as its leading singer. Rudel already had an interest in opera written before the time of Mozart and in the then-neglected era of Italian bel canto opera. Operas of Handel, Donizetti, Bellini, and Rossini were frequently represented on the NYCO stage. Their style was also well-suited to the abilities of Sills and her frequent partner, mezzo-soprano Marilyn Horne, and made the New York City Opera's seasons more exciting than the standard fare offered by the rival Metropolitan Opera Company (which became the NYCO's neighbor at the Lincoln Center in the 1960s). A feature of his seasons was a strong support for American operas.

During his tenure at the NYCO, Rudel also often conducted in major opera centers in Vienna, Munich, Chicago, San Francisco, Paris, Rome, London, Hamburg, Berlin, and even the Met. He was also the first music director of the Kennedy Center in Washington and of the Wolf Trap Festival.

He left the City Opera in 1979 in order to have more time for symphonic conducting. He accepted a position as music director of the Buffalo Philharmonic and frequently conducted the Orchestra of St. Luke's in New York, with which he recorded works of Weill, Schubert, and Mozart on the MusicMasters label. He also conducted the Montreal Symphony Orchestra, the Royal Scottish National Orchestra, and others. Meanwhile, he continued as an opera conductor, appearing at the Met, Teatro Colón in Buenos Aires, the Bastille Opera, Lyric Opera of Chicago, the Royal Opera in Copenhagen, and the Deutsche Oper of Berlin.

He made a number of successful opera recordings and was nominated for Grammy Awards several times, winning once. In 1961, his home nation of Austria presented him a special award for his service to arts and sciences. He was also a Chevalier des Arts et Lettres in France, recipient of awards from Israel and Germany, and holder of several honorary doctorates. In 1996, New York City proclaimed his 75th birthday "Julius Rudel Day," which Rudel himself observed by conducting Madama Butterfly at the Met., Rovi