Devolin was born in Peterborough and grew up in Haliburton. While in high school Devolin was selected as an international exchange student by the Haliburton Rotary Club to spend a year in the Netherlands. After his year abroad, Devolin wanted to become a diplomat and decided to move to Ottawa to study political science at Carleton University, where he graduated with a bachelor's degree in 1985. Two years later he received a master's degree in political science from the Stony Brook University on Long Island, New York.
In 1993, Devolin married Ursula Beachli. They have 2 children, George (2002) and Molly (2004). While they continue to own a home in Haliburton, they currently live in Seoul, South Korea.
In February 2017, Devolin was named Chair of the Asian Studies Graduate Program at Sejong University. As the first non-Korean to hold a senior administrative post at Sejong, Devolin is responsible for all facets of this master's program taught entirely in English and available exclusively to international students. Devolin also serves as liaison between the university and international students, who come from more than a dozen countries around the world, and include foreign diplomats posted in Seoul. At the same time, Devolin has similar responsibilities for Sejong's Global Public Administration undergraduate program, commencing in March 2017. In addition to administrative responsibilities, Devolin teaches graduate and undergraduate courses, where he takes a comparative approach to democracy, politics and government. In terms of research interests, Devolin focuses on the socialization challenges facing North Korean defectors, and the ongoing Korean conflict.
In 1996–97, Devolin and his wife Ursula lived in Korea where he worked as an English professor at Busan University of Foreign Studies.
Devolin began his teaching career in1986 while a graduate student at Stony Brook University, where he taught "Introduction to American Government" and "The Legislative Process". Many years later, while serving in Canada's House of Commons, Devolin was awarded the 2014 Distinguished Alumni Award by Stony Brook University's Political Science department.
In 2013, Barry Devolin announced he would not seek re-election in the 2015 federal election. His former executive assistant, Jamie Schmale, became the Conservative candidate for Haliburton-Kawartha Lakes-Brock, and was subsequently elected as a Member of Parliament in October 2015. Thus ended Devolin's 11 year career in the House of Commons, which included his service as Assistant Deputy Speaker, his last 7 years.
Prior to 2008, Devolin served on several Parliamentary Standing Committees, including as Chair of the Standing Committee on Aboriginal Affairs and Northern Development (2006–08). Devolin was also active in various parliamentary associations, and chaired Canada-Korea, Canada-Azerbaijan and Canada-Belgium. In 2013, South Korean President Lee Myung-buk awarded the prestigious Order of Diplomatic Service Medal (Heung-in) to Devolin, the only Canadian to ever receive it.
In 2004 Devolin was nominated as the candidate for the new Conservative Party of Canada, and was elected in the 2004 election to represent the newly redistributed riding of Haliburton—Kawartha Lakes—Brock. He received 44% of the popular vote, defeating O'Reilly. In the 2006 election Devolin was re-elected with 49% of the vote. He was subsequently reelected in 2008 with 56% of the vote, and in 2011 with 60% of the vote.
Many years earlier, Devolin ran in the 1993 federal election as a member of the Reform Party in the riding of Victoria—Haliburton. Devolin placed second in the election, losing to John O'Reilly of the Liberals. Following the 1993 election, Devolin served as the director of research for the parliamentary caucus of the Reform Party. He spent time working in British Columbia and Korea, and in 1994 returned to Canada to assist Chris Hodgson to seek election to the Legislative Assembly of Ontario for Haliburton—Victoria—Brock. After this, he served as Hodgson's chief of staff. Devolin did not seek the nomination in Haliburton—Victoria—Brock in the 1997 and 2000 federal elections.
Over the years, Devolin held several senior political staff positions in the Canadian and Ontario governments, including Chief of Staff to Ontario Ministers Tim Hudak (1999–2000) and Chris Hodgson (1995–96), Special Assistant for Education to Ontario Premier Mike Harris (1998–99), and Director of Research and Question Period Strategist for the Reform Party of Canada under Preston Manning (1993–94). From 2000–04, Devolin ran Shuter Street Associates, a strategic communications and planning consulting firm in Toronto.
Devolin served twice as campaign manager for Ontario Progressive Conservative candidates: in 1999 for former cabinet minister Brenda Elliott in the riding of Gueph-Wellington; and, In 1987 for Arthur Ward in the riding of Victoria-Halliburton.