On June 26, 2010, leaders of the world's twenty largest economies gathered at the Metro Toronto Convention Centre for a two-day summit that would become synonymous with one of the costliest security operations in Canadian history. The G20 heads of state and government, representing nations responsible for roughly 85 percent of global GDP, arrived to tackle the lingering aftermath of the 2008 financial crisis and chart a course for economic recovery. The summit brought together representatives from the United States, China, Japan, Germany, France, the United Kingdom, Italy, Canada, Russia, India, Brazil, Mexico, South Korea, Indonesia, Saudi Arabia, Turkey, Argentina, South Africa, and Australia, plus additional leaders from invited nations and officials from international organizations including the International Monetary Fund and World Bank.

The summit's agenda reflected the urgent concerns of a world still reeling from financial turmoil. Leaders debated and voted on financial reform measures, evaluated progress on stimulus spending, discussed a controversial global bank tax proposal, and worked to prevent protectionism amid economic fragility. The meeting represented a critical moment in global economic governance, as policymakers sought consensus on regulating the banking sector more stringently and coordinating national recovery strategies. The Canadian government, under Prime Minister Stephen Harper, invested heavily in preparation, deploying unprecedented security measures that would ultimately cost approximately $1 billion, making it the most expensive security operation Canada had ever mounted for a single event.

The summit produced mixed results. While leaders agreed on some coordinated approaches to financial regulation and pledged continued support for stimulus measures, disagreements emerged over the proposed bank tax, which faced resistance from the United States and other nations. The gathering also took place against a backdrop of significant public protest; demonstrations against the G20 and globalization attracted thousands to Toronto's streets, leading to tensions with police and property damage that further defined the event in Canadian collective memory. Though the summit's policy outcomes proved modest, the 2010 G20 meeting reinforced Toronto's position as a venue for global governance and left a lasting imprint on how nations approached international economic coordination in the post-crisis era.