The Confederation of Health Service Employees (COHSE) was a United Kingdom trade union representing workers primarily in the National Health Service.

The union was founded in 1946 with the merger of the Mental Hospital and Institutional Workers Union and the Hospital and Welfare Services Union, with the aim of having one union to represent workers in the National Health Service on its formation.

In 1993, COHSE merged with two other trade unions - NUPE (the National Union of Public Employees) and NALGO (the National and Local Government Officers Association ) - to form UNISON, the largest public sector trade union in the UK.

The union sponsored Labour Party candidates at each Parliamentary election from 1979.