British labour union, an affiliate of the Trades Union Congress, the national organization of British trade unions (trade union). UNISON was created in 1993 through the merger of several unions, including the National Union of Public Employees (formed 1905) and the Confederation of Health Service Employees (formed 1910). It maintains a separate political fund, which supports the activities of the Labour Party.

UNISON's more than 1.3 million workers are employed in the public sector and in private-sector jobs that provide public services. Some two-thirds of its members are women (the union maintains a quota to ensure that women occupy executive positions in rough proportion to their overall membership), and it has organized sections representing the interests of its women, black, disabled, and gay and lesbian members. Workers are also organized along function lines, with separate service groups for workers employed in business and the environment, the community and voluntary sector, education, health care (particularly the National Health Service), local government, and the police.

Each individual member is represented by a local branch consisting of those employees working for a single employer. Above the local branch are 13 regional councils, which are composed of local-branch delegates. Nationally, UNISON's National Delegate Conference, made up of regional delegates, determines policies, which are implemented by a National Executive Committee.