In 1926, Beecham planned to form a permanent Royal Philharmonic Orchestra to serve the BBC and the RPS, but the BBC instead started its own BBC Symphony Orchestra. In 1932, Beecham founded the London Philharmonic Orchestra, financially backed by recording contracts and a contract to serve as the RPS's concert orchestra. Beecham left to take a position with the Seattle Symphony Orchestra when World War II broke out, and the LPO transformed itself into a self-governing organization.

Beecham returned to Britain in 1944 and formed a new orchestra, giving its first concert at the Davis Theatre in Croydon on September 15, 1946, just three weeks after Beecham started hiring musicians. Again, he placed the new orchestra under the RPS rubric, enabling it to take the Royal Philharmonic Orchestra name. In 1948, the RPO became the resident orchestra of the summer Glyndebourne Festival Opera, and in 1950 it became the first British orchestra to tour the United States since before World War I. Feeling his advancing age, Beecham engaged Rudolf Kempe as assistant conductor. When Beecham died in 1961, Kempe became principal conductor.

The orchestra's financial situation immediately worsened. Glyndebourne and the RPS itself declined to renew their contracts, and the RPO was excluded from the London Orchestral Concert Board's schedule of concerts in the new halls on the South Bank. The orchestra re-formed as a self-governing organization, but had to give its concerts in a movie house on the north side of London. Kempe received the titles of Artistic Director in 1964, and Conductor for Life in 1970.

Things took a turn for the better in 1966 when Queen Elizabeth II granted the orchestra its own Royal Charter, enabling it to continue calling itself the Royal Philharmonic Orchestra. After a difficult period following the death of Kempe, the orchestra appointed Antal Dorati, noted for building orchestral discipline and morale, as Conductor-in-Chief (1975-1978). He has been followed by Walter Weller (1980-1985), André Previn (Conductor-in Chief, 1985-1987, and Principal Conductor, 1987-1992), and Vladimir Ashkenazy (Music Director, 1987-1994). Yuri Temirkanov became Principal Conductor in 1992 and remains as Emeritus Principal Conductor. Daniele Gatti, a young and exciting Italian conductor, became Music Director in 1996. Charles Dutoit became Principal Conductor in 2009.

The orchestra is now firmly back in the center of London concert life. It plays its main series at the Royal Albert Hall with a few concerts also given at the Barbican Centre in the City of London. In addition, in an innovative move, it also established itself as the resident orchestra of the Royal Concert Hall in Nottingham, where it gives a series of ten concert programs a year.

The RPO has a 125-release contract with Tring International, the largest contract in history between one orchestra and a record company. It has a close association with Classic FM, the largest commercial radio company in Britain. It has formed two sub-ensembles. The Royal Philharmonic Concert Orchestra is essentially the RPO's "Pops" (or as the British say, "light classical") orchestra. Sharp Edge, a flexible ensemble of 10 to 30 musicians, plays innovative concerts of the newest music.