István Kertész (28 August 1929 – 16 April 1973) was a Hungarian orchestral and operatic conductor who throughout his brief career led many of the world's great orchestras, including the Cleveland, Chicago, Philadelphia, New York, Los Angeles, Pittsburgh, Detroit, San Francisco and Minnesota Orchestras in the United States, as well as the London Symphony, Vienna Philharmonic, Berlin Philharmonic, Royal Concertgebouw Orchestra, Israel Philharmonic, and L'Orchestre de la Suisse Romande.

Kertész was part of a musical tradition that produced fellow Hungarian conductors Fritz Reiner, Antal Doráti, János Ferencsik, Eugene Ormandy, George Szell, János Fürst, Peter Erős, Ferenc Fricsay, and Georg Solti.

Miklós Kertész, born in Szécsény, Hungary into a large Jewish family, was the director of a leather-works and died of appendicitis in 1938.

At the insistence of his mother, and despite the wartime interruptions of air raids, deportations, starvation and invasions by both Germans and later, the Russians, István Kertész continued his musical studies.

The young Kertész, along with his sister, took advantage of Budapest's rich cultural life and attended symphonic or operatic performances almost every evening.

Musically, Kertész was most influenced by László Somogyi, Bruno Walter and Otto Klemperer, then the director of the Budapest Opera.

During this period he had the opportunity to develop a broad symphonic repertoire, leading the Budapest Opera Orchestra from 1955 to 1957, and working as an Assistant Professor of Conducting at the Franz Liszt Academy of Music.

Offered a fellowship to the Accademia Nazionale di Santa Cecilia in Rome, Kertész studied with Fernando Previtali while his wife, Edith Kertész-Gabry sang at the Bremen Opera.

He also conducted performances of Verdi's Rigoletto, Don Carlos, Otello and Falstaff, and Richard Strauss's Salome, Arabella, and Der Rosenkavalier.

Invited to the Salzburg Festival, he conducted Die Entführung aus dem Serail in 1961, and The Magic Flute in 1963.

He made his US debut during the 1961–62 season, also beginning an association with the Israel Philharmonic Orchestra whom he guest-conducted at Tel Aviv's Mann Auditorium in March 1962.

In 1964, Kertész received an appointment as the general music director of the Cologne Opera where he conducted the first German performance of Benjamin Britten's Billy Budd and Verdi's Stiffelio, as well as the Mozart operas La clemenza di Tito, Don Giovanni, Così fan tutte and The Magic Flute.

Pianists Clifford Curzon, Hans Richter-Haaser, Vladimir Ashkenazy and Julius Katchen each made records with Kertész.