The Hundred of Mount Muirhead is a cadastral division of the County of Grey in southeastern South Australia.

[1][2] Two townships lie within the hundred—Millicent and Hatherleigh along with the localities of Sebastopol and Rocky Camp.

Parts of Rendelsham, Furner, Canunda and Mount Burr localities also overlap the hundred.

The hundred includes the northern part of Canunda National Park.

The Mayurra district formed the basis of the early local government body, the District Council of Mayurra, later renamed to Millicent, and likewise Mount Muirhead to the north formed the basis for the District Council of Mount Muirhead (both established in 1888).