The Stock Exchange of Thailand (Thai: ตลาดหลักทรัพย์แห่งประเทศไทย), or SET, is the only stock exchange in Thailand. Founded on 30 April 1975, it is ASEAN’s 2nd largest after Singapore and the world's 25th by market capitalization at US$513 billion (both SET and mai) as of 22 October 2022. From 2015 to June 2020 it was the biggest IPO market in Southeast Asia in terms of accumulated raised fund at USD 17.8 billion (THB 598.0147 billion). It is also the region’s most active bourse for 10 consecutive years with daily trading turnover normally exceeding USD 2 billion.

In recent years, the number of market participants has risen sharply: trading accounts has increased almost 10 times from 2008 to 2022. Based on the number of investors, about 3% of people in Thailand participate in the stock market.

SET index is the oldest and the most cited equity index in Thailand. It made intraday all-time high at 1852.51 on 27 February 2018, surpassing the previous high of 1789.16 on 5 January 1994.

SET has stricter price regulations than some other exchanges, normally disallowing stock prices to rise or drop more than 30% in a day.