Joseph Alan McIsaac (born 18 March 1954) is a Canadian politician, who represented the electoral district of Vernon River-Stratford in the Legislative Assembly of Prince Edward Island as a member of the Liberal Party from 2007 to 2019. He has served as chair of the Standing Committee on Agriculture, Environment, Energy and Forestry, and was a member of the Treasury Board. He has been a member of the Standing Committee on Fisheries, Transportation and Rural Development, the Standing Committee on Public Accounts, and the Standing Committee on Education and Innovation.