The Official Opposition Shadow Cabinet in Canada is composed of Members of Parliament of the main Opposition party responsible for holding the Government to account and for developing and disseminating the party's policy positions.

The Conservative Party of Canada served as the Official Opposition in the 42nd Parliament.

82 MPs have served in the Official Opposition Cabinet in the 42nd Parliament.

Following the 2015 federal election, held on October 19, 2015, the Conservative Party lost power and became the 42nd Parliament of Canada's Official Opposition.

It was led by Rona Ambrose on an interim basis from November 2015 to May 2017.