By-elections to the 28th Canadian Parliament were held to fill vacancies in the House of Commons of Canada between the 1968 federal election and the 1972 federal election.
The Liberal Party of Canada led a majority government for the entirety of the 29th Canadian Parliament, though their number did decrease from by-elections.
Fifteen seats became vacant during the life of the Parliament.
Eleven of these vacancies were filled through by-elections, and four seats remained vacant when the 1972 federal election was called.