Deputy Leader in the Westminster system is the second-in-command of a political party, behind the party leader . Deputy leaders often become Deputy Prime Minister when their parties are elected to government. In opposition, deputy leaders often lead Question Period sessions when the party leader is away. The deputy leader may take on the role of the leader if the current leader is, for some reason, unable to perform their role as leader. Reasons may include: assassination, foreign conference attendance, or illness. They also usually have other responsibilities of party management.

Some Current Deputy Leaders:

• Peter MacKay, Deputy Leader of the Conservative Party of Canada
• John Prescott, Deputy Leader of the British Labour Party (also Deputy Prime Minister of the United Kingdom)
• Bill Blaikie, Deputy Leader of the New Democratic Party of Canada
• Anne McLellan, Deputy Leader of the Liberal Party of Canada (also Deputy Prime Minister of Canada)

See also: Deputy Prime Minister