Michael Vincent Murphy was Government Surveyor on Norfolk Island to 1906 when he became officer in Charge of Norfolk Island Affairs, a post he held till 1913.  He then succeeded Captain C S Elliot as Chief Magistrate.  This Office (CA 6688) was on 21 August 1913 combined with that of Administrator and so Murphy was the first to hold both positions.

On 1 July 1914 Norfolk Island became part of the Commonwealth under the provisions of the Norfolk Island Act, No 15 of 1913, and future Administrators were appointed by the Governor-General and not by the Governor of NSW as in Murphy's case.

In 1919 Murphy left Norfolk Island and was succeeded by Dr A Paton who was Acting Administrator until Lieutenant-General Parnell became Administrator in 1920.  Murphy returned as Acting Administrator for a short period (12 August) 1926 to (31 January) 1927 after the Royal Commission into Norfolk Island Affairs (CA 2304) which recommended that the current Administrator, Colonel Leane (CP 194), be withdrawn.

Murphy's date of birth is subject to further research.