The name Calderdale usually refers to the borough through which the upper river flows, while the actual landform is known as the Calder Valley.

[citation needed] A Roman fort has been excavated in Slack, which is in the neighbouring borough of Kirklees, but its identity is not yet certain.

[citation needed] The metropolitan district of Calderdale was created on 1 April 1974 under the Local Government Act 1972.

It covered the area of eight former districts and part of a ninth, which were all abolished at the same time:[3][4][5] In 2022, Yorkshire Water built an emergency water pipeline from Calderdale to Ponden Reservoir in Haworth as Yorkshire experienced its driest period on record.

[8] The 2021 census showed further changes in the borough, with the White British population declining slightly to 82.7% and the proportion of residents of Pakistani heritage increasing to 8.5%.

These are located at Rastrick (Since 2015), King Cross (Halifax Fire Station), Mytholmroyd, Illingworth, and Todmorden.

[15] In 2014, construction began on a new central library and archive building in Halifax, adjacent to the Piece Hall and the Square Chapel.

A new Elland railway station received planning permission in 2023 and construction is expected to begin in 2024 for a potential opening date of December 2025.

Destinations for services include Bradford Interchange, Huddersfield, Leeds, York, Manchester Victoria, Blackpool North, Wigan North Western, Chester, Warrington Bank Quay, Hull, Preston, Burnley Manchester Road and London King's Cross.

Other sports facilities include North Bridge Leisure Centre (Halifax, Currently Closed), Sowerby Bridge Swimming Pool, Brighouse Leisure Centre and Pool, Todmorden Swimming Pool, The Shay Stadium (Halifax Towns Football Pitch) and Spring Hall (Halifax, Track and field).

The eastern part of the borough, covering Brighouse, Elland, Halifax, Shelf and Sowerby Bridge, is an unparished area.

The Paschal lamb is the emblem of John the Baptist, the patron saint of wool workers.

The crest shows a rose bush with nine white flowers representing the nine former authorities that now comprise the Calderdale district.

The bush is shown growing out of a mural crown, a common feature in municipal arms.