He represented the electoral district of Truro-Bible Hill in the Nova Scotia House of Assembly from 1998 to 2009.
[2] Muir taught as a Frontier College instructor and a high school teacher in Truro before serving as Director of Inspection Services in the Nova Scotia Department of Education.
[2] Muir entered provincial politics in the 1998 election,[3] defeating former Liberal cabinet minister Eleanor Norrie in the Truro-Bible Hill riding.
[6] In August 1999, Muir was appointed to the Executive Council of Nova Scotia as Minister of Health.
[12] On June 26, 2006, MacDonald shuffled his cabinet, moving Muir to Minister of Service Nova Scotia and Municipal Relations.