(October 17, 1883 - September 23, 1973) was a Scottish progressive educator, author and founder of Summerhill school, which remains open and continues to follow his educational philosophy to this day. He is best known as an advocate of personal freedom for children.

Neill was born in Forfar, the son of a schoolteacher. After acting as a pupil-teacher for his father, he studied at the University of Edinburgh and obtained an M.A. degree in 1912. In 1914 he became headmaster of the Gretna Green School in Scotland.

Neill believed that the happiness of the child should be the paramount consideration in decisions about a child's upbringing, and that this happiness grew from a sense of personal freedom in the child. He felt that deprivation of this sense of freedom during childhood, and the consequent unhappiness experienced by the repressed child, was responsible for many of the psychological disorders of adulthood.

The main focus of educational interest and research at that time was the question of how best to produce obedient soldiers who would uncritically follow orders in battle, so Neill's ideas, which tried to help children achieve self-determination and encouraged critical thinking rather than blind obedience, were seen as backward, radical, or at best, controversial.
Neill founded Summerhill School to demonstrate his educational theories in practice. These included a belief that children learn better when they are not compelled to attend lessons. The school is also managed democratically, with regular meetings to determine school rules. Pupils have equal voting rights with school staff.
Neill's Summerhill School experience demonstrated that, free from the coercion of traditional schools, students tended to respond by developing self-motivation, rather than self-indulgence. Externally imposed discipline, Neill felt, actually prevented internal, self-discipline from developing. He therefore considered that children who attended Summerhill were likely to emerge with better-developed critical thinking skills and greater self-discipline than children educated in compulsion-based schools.
These tendencies were perhaps all the more remarkable considering that the children accepted by Summerhill were often from problematic backgrounds, where parental conflict or neglect had resulted in children arriving in a particularly unhappy state of mind. The therapeutic value of Summerhill's environment was demonstrated by the improvement of many children who had been rejected by conventional schools, yet flourished at Summerhill.
Strongly influenced by the contemporary work of Sigmund Freud and Wilhelm Reich, Neill was opposed to sexual repression and the imposition of the strict Victorian values of his childhood era. He stated clearly that to be anti-sex was to be anti-life. Naturally, these views made him unpopular with many establishment figures of the time.
Neill was an admirer and close friend of Wilhelm Reich. Wilhelm Reich and A.S Neill first met in Norway in 1936; Neill was a friend, a student and a patient of Ola Raknes. Neill and Reich remained friends for over twenty years, until Reich's death in 1957.

Wilhelm Reich and A. S. Neill

Reich and Neill                                                    A. S. Neill with Peter Reich at Orgonon 1948

Reich and Neill at the Orgonon lab with students