The Hundred of Crystal Brook is a cadastral unit of hundred located in the Mid North of South Australia in the approach to the lower Flinders Ranges.

[1] It is one of the hundreds of the County of Victoria and was named by Governor James Fergusson after the stream of the same name which flows east to west near the northern border of the hundred.

The town of Crystal Brook and the locality of Merriton are inside the Hundred of Crystal Brook as well as the south half of Nurom and an eastern portion of Wandearah East.

From 1988 the hundred continued to be locally governed as the Town, East and West wards of the District Council of Crystal Brook-Redhill following amalgamation of Crystal Brook and Redhill councils.

From 1997 the hundred became part of the much larger Port Pirie Regional Council following a merger between Crystal Brook-Redhill and the Port Pirie City councils.