Which regional financial crisis began in Thailand in July 1997 and spread across Asia?

The regional financial crisis that began in Thailand in July 1997 and spread across Asia was the Asian financial crisis.

Thailand abandoned its long-standing baht peg to the U.S. dollar on July 2, 1997, after heavy pressure on its foreign-exchange reserves. The baht then depreciated sharply. Investors reassessed other economies with high foreign-currency debts, weak financial sectors, or fixed exchange rates, causing capital flight and stock-market declines across the region.

Indonesia, South Korea, and Thailand received major assistance from the International Monetary Fund, while Malaysia imposed capital controls instead of accepting an IMF program. The crisis also affected Hong Kong and other markets, although the experiences differed by economy.

The episode is often called the Asian financial crisis or the East Asian financial crisis. It was not simply a stock-market crash: currency collapses, corporate debt, banking fragility, and international capital flows were central to the turmoil.