The Stock Exchange of Thailand (SET), is the only stock exchange in the Kingdom of Thailand. It was founded in 1975 and is headquartered in Bangkok, the country's capital, most populous city and economic center. Bangkok is also considered to be a significant business hub in Southeast Asia. The SET is regulated by the Securities and Exchange Commission of Thailand and electronic trading is conducted through SET CONNECT, a trading engine that was launched in 2012. It lists 688 companies with a market cap of $569 billion, which makes it the 23th largest stock exchange worldwide. The SET also houses bonds, ETFs and derivatives and is a member of the Sustainable Stock Exchanges, a project of the United Nations.

Among the listings are well-known and actively traded companies such as the Siam Cement Group, Siam Commercial Bank, Thaioil, Kasikornbank and Intouch Holdings. The main stock index is the SET Index, a broad index that tracks the performance of all common stocks. It is widely seen as the most representative index of the Thai stock market. Related indices are the SET 100 and the SET 50, which track the performance of the 100 and 50 largest and most liquid Thai companies, respectively. All constituents are screened for eligibility and reviewed periodically. The SET also has a Large Cap, Mid Cap, and Small Cap index and indices that reflect the performance of many sectors and industries.