Preston Manning (born June 10, 1942, Edmonton, Alberta, Canada) is a Canadian politician who was the founder and leader of the Reform Party (1987–2000).

Manning was born into a political family. His father, Ernest, was leader of the Alberta Social Credit Party, premier of Alberta (1943–68), and a Canadian senator (1970–83). After graduating from the University of Alberta with a degree in economics (1964), the younger Manning spent three years working on projects for his father. He followed in his father’s footsteps as a populist and an evangelical Christian and gave sermons on the elder’s radio program, the Back to the Bible Hour. After running unsuccessfully as a candidate for the Social Credit Party in the 1965 federal election, he helped his father write Political Realignment (1967), a book that outlined a social conservative agenda for Canadian politics and was a synthesis of marketplace economics and humanitarian socialism. After his father retired from provincial politics, Manning launched a career as a management consultant in the energy industry.

In 1987 Manning returned to the political arena and founded the Reform Party in an effort to gain economic and political power for the western provinces. Four years later the party voted to expand its regional base and become a national force. In The New Canada (1992), Manning outlined a new party mission, which was later adopted. Its goals were to work for a balanced democratic federation of provinces and to recognize that all provinces and citizens were equal. As the first and only leader of the party, Manning formed its name, its statement of principles, and many of its policies, and it came to represent a mixture of his populist views and the conservatism of most party members. Manning saw populism as the “common sense of the common people” and espoused policies that would allow the populace to have more say in the development of public policy.

In 1993 Manning was elected to the Canadian House of Commons for the riding of Calgary Southwest. In the general election held four years later, the Reform Party of Canada received 19 percent of the popular vote and won 60 seats in the House of Commons. Thus, the Reform Party became the official opposition and Manning the leader of the opposition. The party, however, struggled to expand its support beyond social conservatives and the western provinces. In 2000 Manning disbanded the Reform Party and replaced it with the Canadian Reform Conservative Alliance. Later that year he was defeated in his bid to become party leader, and in 2002 he retired from Parliament. He later wrote Think Big: Adventures in Life and Democracy (2003), Faith, Leadership, and Public Life: Leadership Lessons from Moses to Jesus (2017), and Do Something!: 365 Ways You Can Strengthen Canada (2020). In 2005 he founded the Manning Centre for Building Democracy.