The Association of Teachers and Lecturers (ATL) was a trade union, teachers' union and professional association, affiliated to the Trades Union Congress, in the United Kingdom representing educators from nursery and primary education to further education. In March 2017, ATL members endorsed a proposed merger with the National Union of Teachers to form a new union known as the National Education Union, which came into existence on 1 September 2017. At that time, approximately 120,000 individuals belonged to the union, making it the third largest teaching and education union in the UK. ATL had members throughout England, Scotland, Wales, Northern Ireland, the Channel Islands, the Isle of Man, and British Service schools overseas.

A teacher, also called a schoolteacher or formally an educator, is a person who helps students to acquire knowledge, competence, or virtue, via the practice of teaching.