During the Second World War she was a nurse at Battle Hospital in Reading, Berkshire, where she met and married Bob Salisbury. They moved to Melksham, Wiltshire, in 1947 and joined the local Labour Party soon after that.
In 1954, Salisbury was elected to the former Melksham Urban District Council, and later to Wiltshire County Council. In 1960 she became a Justice of the Peace for Wiltshire. In 1982 she was appointed a Commander of the Order of the British Empire for services to local government, and in January 1983 was Gazetted a Deputy Lieutenant for Wiltshire, together with Lord Margadale. She was also a member of the Wiltshire Victoria County History Committee.
When the Conservatives lost control of Wiltshire County Council in 1985, leaving behind them a hung council, Salisbury commented to The Times that there was virtually nothing which she opposed in Jack Ainslie's plan for a new Liberal-SDP administration and almost nothing on which she agreed with the defeated Conservatives. "Where the Liberals put forward measures which seem to be beneficial to the people of Wiltshire, we will support them", she said. With the council remaining hung, she went on to become the first woman Chairman of Council, holding that office from 1989 until 1992. She was a member of the county council for thirty-eight years and was also a member of the Wiltshire and Swindon Fire Authority, standing down from both in 2001.
- List of chairmen of Wiltshire County Council
- Wiltshire Council election, 1989
- Wiltshire Council election, 1997
- OBITUARY: Mrs Mary Salisbury at wiltshiretimes.co.uk
- London Gazette Issue 49236 published 17 January 1983, p. 693
- Wiltshire Victoria County History Committee as at 16 September 1998 from A History of the County of Wiltshire: Volume 16 (1999), p. xiv
- Hugh Clayton, Emerging figure in new Lib-Lab pact An Alliance shire leader cast in Tory mould, in The Times, May 11, 1985; pg. 2; col C
- Brian J Rusbridge, The Municipal Year Book and Public Services Directory 1990 (1990) p. 81
- Press Release: Service of thanksgiving at wiltshire.gov.uk
- Minutes of a Meeting of the Wiltshire & Swindon Fire Authority on Thursday 22 March 2001
- Wiltshire County Council Diary 2001 (Trowbridge, Wiltshire County Council, 2001)