After graduating from Canon Richards High School, Flower's Cove in 2003, Mitchelmore went on to complete a Bachelor of Commerce Honours (Co-op) from Memorial University of Newfoundland.

His university experience enabled him to work for the Department of Innovation, Trade & Rural Development, Newfoundland & Labrador Board of Commissioners of Public Utilities (PUB) and London Offshore Consultants (LOC) Group.

Mitchelmore was employed with the Association of Professional Engineers, Geologists, Geophysicists of Alberta (APEGGA) and Community Business Development Corporation (CBDC) Nortip as a Youth Ventures Coordinator and most recently as a Client Services Officer, a role focused on creating and maintaining employment through business services, financing, skill enhancements, technical assistance, counselling and community economic development.

He has been engaged at the local, regional, provincial and national level, serving as the vice-President of the Straits-St. Barbe Chronic Care Corporation; Junior Achievement, Regional Chair; Director and Member of the Canadian Community Economic Development Network; co-Chair of Emerging Leaders; and Director with Nordic Economic Development Corporation.

[7] Mitchelmore was re-elected in the 2015 provincial election in the redistributed district of St. Barbe-L'Anse aux Meadows as a Liberal candidate and was subsequently appointed to cabinet.