The LSO was founded in 1904 as an independent, self governing organization, the first such orchestra in the UK. It played its first concert on 9 June of that year, with Hans Richter conducting. He remained principal conductor until 1911, when Edward Elgar took over for a year, leading six concerts as principal conductor.

More recently, its principal conductors have included Pierre Monteux (1961–64), Istvan Kertesz (1965–68), André Previn (1968–79) and Claudio Abbado (1979–88). From 1988-1995, the American Michael Tilson-Thomas took over, and in 1995, became principal guest conductor. Sir Colin Davis served as the LSO's Principal Conductor from 1995-2006, and in 2007 took the post of President of the orchestra. On 1 January 2007, Valery Gergiev became the LSO's Principal Conductor. Previn holds the title of Conductor Laureate. In 2006, Daniel Harding became the co-principal guest conductor alongside Tilson Thomas. Richard Hickox is the Associate Guest Conductor of the LSO.
The LSO became the first British orchestra to play overseas when it went to Paris in 1906. The LSO was due to sail on the RMS Titanic for a concert in New York in April 1912 but fortunately had to change the booking at the last minute. It was also the first to play in the United States, in 1912, and in 1973 it was the first to be invited to take part in the Salzburg Festival. It continues to make tours around the world.

In 1966 the London Symphony Chorus (LSC) was formed to complement the work of the LSO. with more that two hundred amateur singers, the LSC maintains a close association with the LSO; however it has developed an independent life, which allows it to partner other leading orchestras.

The LSO has long been considered the most extraverted of the London orchestras. For most of its life it refused to allow women to become members, ostensibly on the grounds that women would affect the sound of the orchestra (there has been a similar controversy at the Vienna Philharmonic Orchestra). There is an air of youthful high spirits to much of its music-making that is shown off in performances of such composers as Berlioz and Prokofiev. The LSO has often had internationally-known players as wind soloists, including such artists as James Galway (flute), Gervase de Peyer (clarinet), Roger Lord (oboe), Osian Ellis (harp), John Georgiadis (violin) and Barry Tuckwell (horn). Like most ensembles, the orchestra has a great ability to vary its sound, producing very different tone colours under such diverse conductors as Stokowski (with whom it made a series of memorable recordings), Adrian Boult, Jascha Horenstein, Georg Solti, André Previn, George Szell, Claudio Abbado, Leonard Bernstein, John Barbirolli, and Karl Böhm, who developed a close relationship with the orchestra late in his life. Böhm and Bernstein each held the title of LSO President in their later years.

Clive Gillinson, a former cellist with the orchestra, served as the LSO's Managing Director from 1984 to 2005, and is widely credited with bringing great stability to the LSO's organization after severe fiscal troubles.[1] Since 2005, Kathryn McDowell is the Managing Director of the LSO.[2]