The Inland Waterways Association (IWA) is a registered charity in the United Kingdom which was formed in 1946 to campaign for the conservation, use, maintenance, restoration and sensitive development of British canals and river navigations.

The canals of the United Kingdom are a major part of the network of inland waterways in the United Kingdom. They have a varied history, from use for irrigation and transport, through becoming the focus of the Industrial Revolution, to today's role of recreational boating. Despite a period of abandonment, today the canal system in the United Kingdom is again increasing in use, with abandoned and derelict canals being reopened, and the construction of some new routes. Canals in England and Wales are maintained by navigation authorities. The biggest navigation authorities are the Canal & River Trust and the Environment Agency, but other canals are managed by companies, local authorities or charitable trusts.