Sir Neville Marriner, CH, CBE (15 April 1924 – 2 October 2016) was an English conductor and violinist. Described as "one of the world's greatest conductors", Gramophone lists Marriner as one of the 50 greatest conductors and another compilation ranks Marriner #14 of the 18 "Greatest and Most Famous Conductors of All Time". He founded the Academy of St Martin in the Fields, and his partnership with them is the most recorded of any orchestra and conductor.

Marriner was born in Lincoln, England, the son of Herbert Marriner, a carpenter, and his wife Ethel (née Roberts). He was educated at Lincoln School (then a grammar school), where he played in a jazz band with the composer Steve Race. He initially learned the violin as well as the piano from his father, and later studied the violin with Frederick Mountney.

In 1939 he went to the Royal College of Music in London, where he studied with the violinist William Henry Reed and was able to play among the second violins of the London Symphony Orchestra, conducted by Henry Wood, because many of its members had joined up after the outbreak of the Second World War. He joined up himself in 1941, serving in a reconnaissance role in the British Army, but was invalided out in 1943 with kidney problems. He returned to the Royal College, although Reed had died in the meantime. He then attended the Paris Conservatoire, where he studied with the violinist René Benedetti.

Marriner was briefly a music teacher at Eton College. In 1948, he became a professor of the Royal College of Music. In 1948 or 1949, he took up the position of second violinist of the Martin String Quartet, continuing to play with the quartet for 13 years. He had met the harpsichordist Thurston Dart while recuperating from kidney damage during the war, and they formed a duo together, which expanded to the Virtuoso String Trio with Peter Gibbs. These were the precursors to Dart's Jacobean Ensemble, in which Marriner played from 1951. He played the violin in two London orchestras: the Philharmonia Orchestra in the early 1950s, and the London Symphony Orchestra (LSO), i.a. under Josef Krips, as principal second violin (1954–69). He also played with the chamber orchestras of Reginald Jacques and Boyd Neel, as well as the London Mozart Players.

In 1958 he founded the Academy of St Martin in the Fields; initially a twelve-member chamber ensemble, it soon expanded to a chamber orchestra, and attracted musicians of a high calibre including Dart, Iona Brown, Christopher Hogwood and Alan Loveday. Marriner recorded prolifically with the Academy. The first recordings in the early 1960s, with Marriner both conducting and playing lead violin, were successful, leading Pierre Monteux, then the LSO's conductor, to encourage Marriner to shift his focus to conducting. Marriner had studied the subject with Monteux at his school in Hancock, Maine, in the United States, from around 1950.

Marriner was the founder and first music director of the Los Angeles Chamber Orchestra, from 1969 to 1978. From 1979 to 1986, he was music director of the Minnesota Orchestra. He was principal conductor of the Stuttgart Radio Symphony Orchestra from 1986 to 1989. Except for 1974 to 1980 during which Iona Brown was the director, he remained the musical director of the Academy of St Martin in the Fields until 2011, when he was succeeded by Joshua Bell, continuing to hold the title of Life President until his death. He also conducted many other orchestras, including the New York Chamber Orchestra, Gulbenkian Orchestra, Israel Chamber Orchestra, Australian Chamber Orchestra and Vienna Philharmonic. He continued to conduct into his nineties, becoming the oldest conductor of a Proms concert in 2014, aged 90.

His obituary in The Telegraph praises the Academy of St Martin in the Fields' interpretations of baroque and classical music as "fresh, technically brilliant", and describes them as a "revelation". Marriner preferred modern instruments and effects, and his work came under criticism by Hogwood, among others, for not striving for an "authentic" sound. He later expanded the Academy's repertoire to include Romantic and early-modern music.

Marriner made over 600 recordings covering 2,000 different works – more than any conductor except Herbert von Karajan. He recorded for various labels, including Argo, L'Oiseau Lyre, Philips and EMI Classics. His recorded repertoire ranges from the baroque era to 20th-century British music, as well as opera. He supervised the Mozart selections for the soundtrack of the Oscar-winning 1984 film Amadeus; it became one of the most popular classical music recordings of all time, selling over 6.5 million copies.