U3A groups around the UK are members of the National Third Age Trust. Their main purpose is to encourage lifelong learning for those no longer in full time gainful employment.

The original seeds were sown at the Summer School of the Universite du Troisieme Age, held in Toulouse in 1972. This led to the formation of the International Association of U3A's (AIUTA).

The U3A in the UK was started by the creation of the Third Age Trust in 1982 as a registered charity and limited company. Contrary to the French experience, there was no support from UK universities. It was realised that 'Third Agers' had the skills to organise and teach in their own autonomous learning groups, and local U3A's were formed.

Learning is for pleasure and no qualifications are involved.

There are 614 U3A groups in the UK with a total membership (December 2006) of 167,373.
(An increase of 40 U3A's and 13,930 members since February 2006)