Muswellbrook Shire is a local government area in the Upper Hunter region of New South Wales, Australia. The Shire is situated adjacent to the New England Highway and the Hunter railway line. Muswellbrook Shire was established on 1 July 1979 from the amalgamation of the Municipality of Muswellbrook with the adjacent Denman Shire, which had been called Muswellbrook Shire between 1907 and 1968. The mayor of the Muswellbrook Shire Council is Cr. Jeffrey Drayton.