Born on 11 December 1929 in Dunfermline, Scotland Kenneth MacMillan had a difficult childhood. He lost his mother at an early age and his father was injured during World War I and declared bankrupt in 1935. Following the death of MacMillan's mother his father withdrew more and more from family life.
Growing up in Great Yarmouth, MacMillan took his early dance lessons from Phyllis Adams and after only nine months was accepted on a scholarship to the Sadler's Wells Ballet School (now the Royal Ballet School). He studied there for a year before, in 1946, he became a founding member of Sadler's Wells Theatre Ballet. Whilst studying, he met and gained the support of Ninette de Valois, something he was to enjoy wholeheartedly for the rest of his life. In 1948 he moved to Sadler's Wells Ballet, but returned to the Theatre Ballet four years later.
He began choreographing for the company's choreographic group and two promising early works, Somnambulism (1953) and Laiderette (1954) led de Valois to commission a work from the 25-year-old MacMillan. Danses concertantes was first produced in January 1955. He continued to dance, but gradually gave it up in favour of his true vocation. A string of successful works followed including Solitaire (1956), The Burrow (1958), Le Baiser de la fée and The Invitation (1960), The Rite of Spring (1962), La Création du monde (1964) The Song of the Earth and his first full-length work, Romeo and Juliet (1965). The year he choreographed Romeo and Juliet, which has become one of his best-loved pieces, he was appointed Resident Choreographer at The Royal Ballet.
MacMillan was Director of the Berlin Opera Ballet, 1966 - 69, and was made Director of The Royal Ballet in 1970. He continued to choreograph and produced a string of masterpieces: Valses nobles et sentimentales (1966), Anastasia (1971), The Seven Deadly Sins (1973), Manon and Elite Syncopations (1974), Requiem (1976), Mayerling (1978), Isadora (1981), The Prince of the Pagodas (1989) and The Judas Tree (1992). In 1977, aged only 48, he retired as Director and took up the position of Principal Choreographer for The Royal Ballet. He was knighted in 1983.
MacMillan died of a heart attack on 29 October 1992. He was backstage at Covent Garden, at a revival of his Mayerling. The same evening, Birmingham Royal Ballet was dancing his Romeo and Juliet in Birmingham. He is remembered as one of the great choreographers of the 20th century who was unafraid of confronting controversial issues in his ballets (for example The Invitation and The Judas Tree). He often dwelled on the darker side of human nature and sexuality and some of his works centred on characters who would be considered outsiders in modern society. At the same time, ballets such as Elite Syncopations showed that he was capable of creating works of great wit and charm.