In 1947 an orchestral playing scheme was pioneered in North London which developed into the Haringey Young Musicians' Symphony Orchestra. It became apparent that a similar demand existed among adults, and in the mid-1950s the Tottenham Municipal Orchestra was formed. In 1965, with the reorganisation of the boroughs, this was renamed the Haringey Symphony Orchestra. For many years it was part of the borough's adult education programme, but in 1987 it became independent and took on charitable status. With the demise over the years of many orchestras in the area, in 1995 the name was changed to North London Symphony Orchestra to reflect its wider base.

David Lardi has been the orchestra's conductor and musical director since 1975. His predecessors include Harry Legge OBE, Leslie Orrey and Roy Slack.

From the start, the orchestra has frequently engaged soloists of the highest calibre, among them Dennis Brain, Alfredo Campoli and Gervase de Peyer. In more recent years it has pursued a policy of encouraging leading performers of the younger generation, including Nigel Kennedy, Tasmin Little, Howard Shelley, Raphael Wallfisch, Anna Markland and Emma Johnson - the last two being BBC Young Musician of the Year winners.

Since 1975 the orchestra's repertoire has concentrated on major works from the mid-19th and early 20th century period, though it has not strictly observed these limits. Composers who have figured in its programmes include Beethoven, Brahms, Borodin, Bruckner, Dvorak, Elgar, Franck, Gershwin, Holst, Mahler, Peter Maxwell Davies, Mendelssohn, Prokofiev, Ravel, Rachmaninov, Saint-Saens, Schubert, Sibelius, Shostakovich, Stravinsky, Sullivan and Tchaikovsky.

For many years the orchestra played at the old Alexandra Palace, where it gave the last classical concert before the building burnt down. Appropriately, it performed the reopening concert in the rebuilt Great Hall in 1988. Frequent charity concerts have raised many thousands of pounds for various organisations, including the British Council for the Prevention of Blindness, the Lord Mayor's Appeal, the North London Hospice and the NSPCC.

Since December 2000 the NLSO's regular concert venue has been Palmers Green United Reformed Church, Fox Lane, Palmers Green, N13.