Barnhart was born in Saltcoats, Saskatchewan. He completed his Bachelor of Arts in history in 1967 and in 1968, he took a job teaching grades 10 and 11 history at North Battleford Collegiate Institute. In 1968, after only four months of teaching, he was appointed Clerk of the Saskatchewan Legislative Assembly, the youngest to take on such a position across the Commonwealth. During his tenure, he worked on his Master of Arts at the University of Regina, completing it in 1977. In 1989, Governor GeneralJeanne Sauvé, on the advice of Prime MinisterBrian Mulroney, appointed Barnhart to Clerk of the Senate, and thereby Clerk of the Parliaments. After five years, which included contributing to the failed Charlottetown Accord, he resigned from his position in the Senate. He returned to the University of Saskatchewan, where he completed his Doctorate in 1998. From 2000 to 2005, he served as Secretary of the University of Saskatchewan. He retired to teach political studies classes, specializing in Canadian politics, government and the Canadian Senate. In 2001, Barnhart's book Peace, Progress and Prosperity, which provided the first detailed biography of Saskatchewan's first premier, Thomas Walter Scott, was first published. Some of his other works include Saskatchewan's Premiers of the Twentieth Century, Building for the Future; a photo journal of Saskatchewan's Legislative Building and Parliamentary Committees: Enhancing Democratic Governance. On April 28, 2006, Canadian Prime Minister Stephen Harper announced that Gordon Barnhart would replace Lynda Haverstock as Lieutenant-Governor of Saskatchewan. He was sworn in on August 1, 2006. Barnhart's term ended on March 22, 2012, when he was replaced by Vaughn Solomon Schofield. The University of Saskatchewan announced that Barnhart would return to the faculty of the Department of History as of April 1, 2012 as an adjunct professor. On May 21, 2014, it was announced that Barnhart had been appointed interim President at the University of Saskatchewan to replace Ilene Busch-Vishniac who was fired. As such, he becomes the first former Lieutenant Governor to serve in this capacity. He served as president until October 24, 2015, when he was succeeded by Peter Stoicheff. On June 30, 2014, Barnhart was named a Member of the Order of Canada.
As Lieutenant-Governor
As lieutenant-governor, Barnhart carries out such duties as reading throne speeches, swearing in premiers and cabinet ministers, opening legislative sessions, approving legislation and bestowing honours to Saskatchewan citizens. Upon being sworn in, Barnhart expressed his respect and admiration for his predecessors. As an academic, he expects to focus his efforts on education. He also plans on travelling a great deal to continue the office's accessibility to average Saskatchewanians provided by Haverstock. Barnhart hosted hundreds of visitors on the occasion of his first New Year's Levee at Government House in 2007, a traditional event that lieutenant-governors in Regina have hosted since 1884. Barnhart also initiated the "Lieutenant-Governor's Leadership Forum", which will accept eighteen grade 11 and 12 students each year from 2007 till 2011 to tour the province, meet successful leaders in various fields, and to develop the students' own leadership abilities.