The Auditor General is required by the Auditor General Act to audit government departments, agencies, and Crown corporations and the Public Accounts of Canada. The Office promotes: accountable government, an ethical and effective public service, good governance, sustainable development, and the protection of Canada's legacy and heritage.

The Office does this by: conducting independent audits and studies that provide objective information, advice, and assurance to Parliament, government, and Canadians; working collaboratively with legislative auditors, federal and territorial governments, and professional organizations; and providing a respectful workplace in which our diverse workforce can strive for excellence and realize their full career potential.

The Auditor General reports directly to the House of Commons, through the Speaker.

The position of Commissioner of the Environment and Sustainable Development was created as part of the Office of the Auditor General of Canada, following changes to the Auditor General Act in 1995. The role of the Commissioner is to assist parliamentarians in their oversight of the federal government's efforts to protect the environment and foster sustainable development, by providing them with objective, independent analysis and recommendations. Making the government accountable for greening its policies, operations and programs is a key part of the Commissioner's mandate. The Commissioner monitors and reports annually to the House of Commons on progress toward sustainable development. The Commissioner assists the Auditor General with environmental and sustainable development duties.