On May 20, 2015, Mitchell was appointed to the Executive Council of Prince Edward Island as Minister of Communities, Land and Environment.[4][5] On January 10, 2018, Mitchell was moved to Minister of Health and Wellness in a cabinet shuffle.[6]
From May 8 to September 9, 2019, he served as interim leader of the Liberal Party on Prince Edward Island.
On September 3, 2020, he stepped down from his political position as MLA for Charlottetown-Winsloe, after thirteen years in political service for both provincial districts.[3]