Knussen’s death was announced by his publisher Faber Music, who described him as “our beloved House Composer for over 40 years” who had an “extraordinary” impact on the UK and global musical community.
Born in Glasgow in 1952 and raised near London, Knussen composed his first symphony aged 15. His father Stuart was the principal double bassist of the London Symphony Orchestra.
He previously worked with the BBC Symphony Orchestra as Artist in Association between 2009 and 2014.
Among his best-known work was his collaboration with American illustrator and children’s author Maurice Sendak on an operatic adaption of the former’s Where The Wild Things Are series.
He received several awards during his career including the Ivor Novello Award for Classical Music and the 2015 Queen’s Medal for Music.
Alan Davey, Controller BBC Radio 3, BBC Proms and BBC Orchestras and Choirs, said: “Olly’s death is devastating - he is a towering and irreplaceable figure in British music and had many associations over the years with BBC Symphony Orchestra, BBC Proms and BBC Radio 3.
“His compositions had such strength, economy and clarity. He selflessly championed the music of fellow composers and was an all-round lovely, thoughtful, engaging man who will be hugely missed by everyone. Our thoughts are with his family and friends.”
Classic FM broadcaster John Suchet also paid tribute to Knussen, for whom he spoke during a ceremony in which he received an Honorary Doctorate from the Royal Academy of Music.
He shared a picture on social media of the late composer in university robes with a walking stick and a scroll. Alongside it he wrote: “Sad to learn of death of composer and conductor Oliver Knussen.
“Privileged to have read his citation as he received Honorary Doctorate from the Royal Acadamy of Music just last week.”
The BBC Symphony Orchestra’s official Twitter profile also posted a tribute to Knussen. It said: “We are deeply saddened to hear that Oliver Knussen has died.
“Artist in Association of the BBC Symphony Orchestra from 2009 to 2014, he was a good friend to the Orchestra and conducted many wonderful concerts.
“Olly will be sadly missed and our thoughts are with his family and friends.”
Knussen leaves a daughter, Sonya, who is a classical singer. His wife Sue, a producer of music programmes, died in 2003.