John Edward (Ed) Broadbent (born March 21, 1936) is a Canadian social democratic politician and political scientist. He was leader of the federal New Democratic Party from 1975 to 1989. As a result of the 2004 Canadian election he returned to Parliament as the NDP Member of Parliament for Ottawa Centre.

Broadbent was a university professor when he ran and won election to the Canadian House of Commons from Oshawa in the 1968 general election. In 1971 he ran for the leadership of the party but lost to David Lewis at the NDP leadership convention. He won the 1975 contest to succeed Lewis and went on to lead the party through three elections.

At various times in the 1980s polls showed that Broadbent was the most popular party leader in Canada.

Under his leadership, the NDP reached its highest number of seats (43) in the 1988 federal election. Broadbent was also the only leader ever to take the NDP to first place in public opinion polling, although he was not successful in translating this into an election victory.

When Broadbent stepped down after 15 years as federal leader of the NDP in 1989, he was succeeded by Audrey McLaughlin. In the decade following Broadbent's retirement from politics, the federal NDP flagged.

Broadbent was director of the International Centre for Human Rights and Democratic Development from 1989 to 1996. In 1993 he was made an Officer of the Order of Canada and was promoted to Companion in 2001.

With the encouragement of the new federal NDP leader, Jack Layton, Broadbent returned to politics (with the aid of a humorous and popular TV commercial wmv format) to successfully run for Parliament in the riding of Ottawa Centre, where he now lives. He defeated Liberal Party of Canada candidate Richard Mahoney, a close ally of Prime Minister Paul Martin.

In the NDP shadow cabinet, Broadbent is Critic for Democracy: Parliamentary & Electoral Reform, Corporate Accountability as well as Child Poverty.

He has a Ph.D. in political science from the University of Toronto (1965).