The first University of the Third Age was established in Toulouse, France, in 1972, to improve the quality of life for older people by giving them access - at moderate fees - to non-credit courses in the humanities and natural sciences at the established degree granting universities. The term "third age" denotes the age of retirement, following the first age of childhood and schooling and the second age of vocational employment. The idea spread rapidly in France and then to other countries of continental Europe. An International Association of Universities of the Third Age was established in 1975. 

In 1981 the idea was introduced to Britain by a group based at the University of Cambridge. As Britain had, since early in the century, provided adult education at a moderate fee through co-operation of the Universities and the Workers' Educational Association, the Cambridge group adopted the idea of a self-help university - a kind of intellectual democracy - in which there would be no distinction between teachers and taught. All members would be encouraged to participate, either by teaching, learning or assisting with planning and administration. This self-help approach reduces the need for dependence on outside resources. 

In this environment learning is an end in itself; individuals choose subjects they like from the courses offered. No entry qualifications are required, and no awards are given. 

The first U3A in Australia was established in Melbourne in 1984 and since then campuses (or branches) have been established in all states and territories, and the movement has spread to New Zealand. 

Courses are held mainly in the daytime and, where possible, in community centres, libraries and other public buildings at little or no rent. Space is sometimes found in TAFE colleges. Courses vary in length from 4 to 40 weekly meetings. Single lectures and one-day courses are also held. Subjects include the humanities and sciences and some practical arts and crafts. Field excursions, over several days are sometimes arranged; and overseas tours, based on literature, languages and history are occasionally offered. (Extra fees are involved for excursions and tours). The volunteer teachers and  leaders of courses are retired people with professional skills, or people who have had a lifelong hobby. Many are retired teachers from schools or tertiary institutions. 

Administrative work is done by volunteers. The work includes receiving enquiries, enrolling members, arranging publication of courses to be offered, and finding venues for the courses. Newsletters are issued to members several times a year and members then call (if there is an office) or telephone to enrol in a course. 

Membership fees vary according to the operational fees of particular U3A's, but are moderate. No further fee is charged when members enrol in a course. Members do pay for photocopies of lecture notes and for language text books. 

The Adelaide U3A was the first to be established in South Australia in 1986 by the efforts of Colin Lawton.