Governor General Michaëlle Jean, acting on the advice of Prime Minister Stephen Harper, issued writs of election for the by-elections on October 4.
The riding of Cumberland—Colchester—Musquodoboit Valley had been vacant since April 30, 2009, when Bill Casey resigned to accept a posting from the provincial government of Nova Scotia.
[19] The three seats were vacant due to the resignations of Inky Mark, Judy Wasylycia-Leis, and Maurizio Bevilacqua from the House of Commons.
A by-election call was pending in the Alberta federal riding of Calgary Centre-North, where Conservative MP Jim Prentice announced on November 4, 2010 he was resigning as Environment Minister effective immediately and that he would be resigning as Member of Parliament for Calgary Centre-North by the end of the year to take a job as vice-chairman of the Canadian Imperial Bank of Commerce.
[26] Current Calgary-Foothills MLA Len Webber and recent aldermanic candidate Sean Chu were also rumored to be testing the waters.
However, Liberal leader Michael Ignatieff appointed Stephen Randall – a University of Calgary professor and the former dean of the Faculty of Social Sciences – as the party's candidate on January 6, 2011.
A by-election was pending in the Quebec federal riding of Haute-Gaspésie—La Mitis—Matane—Matapédia, where Bloc Québécois MP Jean-Yves Roy resigned on October 22, 2010 as a result of chronic health problems.
A by-election was pending in the British Columbia federal riding of Prince George—Peace River due to the resignation of Conservative MP Jay Hill on October 25, 2010.
[30] Notably, in his resignation announcement Hill appeared to suggest that he expected the 41st federal election to be called before a by-election could take place in this riding.
[31] Persons seeking the Conservative Party nomination were former Prince George mayor Colin Kinsley,[30] Tumbler Ridge councilor Jerrilyn Schembri, Prince George city councilor Cameron Stolz, Fort St. John councillors Don Irwin and Dan Davies and Conservative riding association CEO Bob Zimmer.