Rhymney Valley (Welsh: Cwm Rhymni) was one of six local government districts in Mid Glamorgan from 1974 to 1996.

Mid Glamorgan County Council provided county-level services to the district.

[3][4] In 1996 the district was abolished, merging with neighbouring Islwyn to become the new unitary Caerphilly County Borough.

[5] The first election to the council was held in 1973, initially operating as a shadow authority before coming into its powers on 1 April 1974.

With bus deregulation in 1986 the buses passed to Inter Valley Link Limited, owned by the district council at "arms length".