Steven MacKinnon was elected in 2015 as the Member of Parliament for Gatineau (Québec), and is the Government House Leader.

Prior to his election to Parliament, Mr. MacKinnon was senior vice president at a global public affairs consultancy, where he was a practice director for mergers, acquisitions and financial communications. He has been involved in national and international transactions worth hundreds of billions of dollars. Bloomberg recognized his practice as Canada's leading mergers & acquisition advisory, which was also a recipient of the Canada-China Business Council's Gold Award.

Mr. MacKinnon is an experienced figure in the Liberal Party of Canada, which he served as national director from 2003 to 2006, serving also as an advisor to former Prime Minister Paul Martin. In 2009, he was Co-Chair of the party's Reform Committee, and he was the Chief Returning Officer for the national Liberal leadership contest in 2013. He also served as an advisor to New Brunswick Premier Frank McKenna for eight years. Over the course of his career, Mr. MacKinnon has participated in constitutional negotiations, the negotiation of trade agreements, labour negotiations, and major health, education, and election reforms. He has volunteered with organizations involved in combatting literacy and domestic violence.

In January 2017, Mr. MacKinnon was appointed Parliamentary Secretary to the Minister of Public Services and Procurement (PSPC) by the Prime Minister. In October 2019, he was re-elected as MP for Gatineau and continues as Parliamentary Secretary at PSPC.

Mr. MacKinnon holds a bachelor's degree in Business Administration from the Université de Moncton and a master’s in Business Administration (MBA) from Queen's University. Steven resides in Gatineau with his spouse Janelle and their three children, Liam, Cassandra, and Alexander.