The Luxembourg Philharmonic Orchestra (Luxembourgish: Lëtzebuerger philharmoneschen Orchester, French: Orchestre philharmonique du Luxembourg), abbreviated to OPL, is a symphony orchestra based in Luxembourg City, Luxembourg. The orchestra formerly performed at the Grand Théâtre de la Ville de Luxembourg and the Conservatoire de Luxembourg. Its current home is the Philharmonie Luxembourg, a large concert hall opened in 2005 in the Kirchberg quarter in the northeast of the city.
The orchestra was founded in 1933 as the in-house orchestra of RTL Radio, named the RTL Grand Symphony Orchestra (French: Grand orchestre symphonique de RTL); Henri Pensis was its founder and first music director. After his initial tenure from 1933 to 1939, Pensis went into exile in the USA in the wake of World War II. He returned to Luxembourg in 1946 to resume direction of the orchestra. After Pensis died in 1958, Carl Melles was the orchestra's music director in 1958. Louis de Froment subsequently became music director and held the post from 1958 to 1980. Leopold Hager succeeded de Froment in 1981, and served for 15 years to 1996.
Following the 1991 privatisation of the Compagnie Luxembourgeoise de Radiodiffusion, in 1995, RTL decided not to renew its contract with the orchestra. Subsequently, the Luxembourg government established the Henri Pensis Foundation to allow for the orchestra to continue its existence. In 1996, the orchestra acquired its current name under its new auspices.