may refer to:
- Trade unionism, support for trade unions
- Community Unionism, describes the various ways in which trade unions can work with communities and community organisations
- Craft unionism, an approach to union organizing in the United States and elsewhere that seeks to unify workers in a particular industry along the lines of the particular craft or trade that they work in
- Dual unionism, the development of a union or political organization parallel to and within an existing labor union
- Industrial unionism, a labor union organizing method through which all workers in the same industry are organized into the same union
- New Unionism, a term which has been used twice in the history of the labour movement to describe moves to broaden the union agenda
- Open-source unionism, a term coined by academics Richard B. Freeman and Joel Rogers to explain a possible new model for organizing workers
- Social Movement Unionism, a trend of theory and practice in contemporary trade unionism
- Student unionism in Australia, student organisations at Australian universities known variously as student associations, student guilds, student unions, or student representative councils
- Voluntary student unionism (VSU), a policy under which membership of – and payment of membership fees to – university student organisations is voluntary
is the support of the British constituent countries remaining part of the United Kingdom state. The most notable movements to this end are:
- Unionism in Ireland, support for Ireland (or Northern Ireland) being part of the United Kingdom, as opposed to (part of) a Republic of Ireland or an independent Northern Ireland.
- Unionism in Scotland support for Scotland remaining as part of the UK.