Steven W. Langdon (born July 15, 1946) is a Canadian academic, politician, economist, and former parliamentarian.
Langdon was re-elected in the 1988 election and stood as a left-wing candidate to succeed Ed Broadbent in the 1989 NDP leadership convention.
He finished third behind Audrey McLaughlin, the eventual winner, and Dave Barrett.
He lost his seat in the 1993 election along with all of Ontario's federal NDP MPs.
Since leaving politics, Langdon has worked as an adjunct research professor in the department of economics at Carleton University in Ottawa.