The orchestra was founded in 1945 by Walter Legge, and although it did give the occasional live concert, it was mainly intended to be a recording orchestra for EMI, where Legge was an executive. On Tuesday 10 March 1964, Legge announced that he was going to suspend the Philharmonia Orchestra. At a recording session with Otto Klemperer, a meeting was convened where those present unanimously agreed that they would not allow the Orchestra to be disbanded. Klemperer gave his immediate support, and on 17 March 1964 the Orchestra elected their own governing body and adopted the name "New Philharmonia Orchestra". The inaugural concert of the New Philharmonia Orchestra under its own auspices took place on 27 October 1964. It was a performance of Beethoven's Ninth Symphony, conducted by Klemperer, who was now Honorary President of the Orchestra.
The orchestra gave many more live performances after it became self-governing than it had under Legge's stewardship. Continuing as the "New Philharmonia Orchestra," it reacquired the rights to the name "Philharmonia Orchestra" in 1977, and has been known by that name ever since.
In its early years, many prominent conductorss made recordings with the ensemble, including Arturo Toscanini, Wilhelm Furtwängler and Herbert von Karajan, who recorded all the Beethoven symphonies with it. These early recordings have helped the orchestra to its title of most recorded orchestra. It has made over a thousand records in total. It was Otto Klemperer, however, who became most closely associated with the group, and in 1959 he became its first principal conductor.
Klemperer's close work with the orchestra was acknowledged when he was given the title of Life Conductor. He retired from conducting in 1971, but was officially still its principal conductor until his death in 1973. For those two intervening years, Lorin Maazel held the post of Associate Principal Conductor (1971-73), and was effectively the principal conductor. Riccardo Muti was principal conductor from 1973 to 1982; he was followed by Giuseppe Sinopoli (1984-94). In 1997, Christoph von Dohnányi took up the post.
Other London-based orchestras include the London Symphony Orchestra, the Royal Philharmonic Orchestra, the English Chamber Orchestra, the London Philharmonic Orchestra and the BBC Symphony Orchestra.