Global Affairs Canada (GAC) is the federal department responsible for managing Canada's diplomatic and consular relations, international trade, and foreign aid. Headquartered at the Lester B. Pearson Building at 125 Sussex Drive in Ottawa, Ontario, the main office acts as the core command center for shaping Canadian foreign policy. The headquarters team coordinates nationwide and global strategies, supporting the Minister of Foreign Affairs, the Minister of International Trade, and the Minister of International Development.

The main office in Ottawa directs a vast network of over 175 missions, embassies, and high commissions spread across the globe. Policy makers and analysts at this central site design programs for global peace, human rights, and international law. They also manage the Trade Commissioner Service to help Canadian companies export goods and find new economic opportunities overseas.

Additionally, the headquarters hosts the 24/7 Emergency Watch and Response Centre, which assists citizens facing crises abroad. Leadership teams inside the building work with international partners to deliver humanitarian aid and fund sustainable poverty-reduction projects. Through these coordinated domestic and international efforts, the headquarters ensures Canada's values remain active in a changing world.