The article analyzes the participation of the overseas Chinese in the economic development of the Kingdom of Thailand during the 20th - beginning of the 21st centuries. Throughout the latter part of the 19th century - first half of the 20th century a large number of Chinese people have migrated to settle in Thailand. Chinese settlers and their descendants had become active participants in the economic life of the Thai society in the 20th century and they continue to play an important role in the country’s economy in the beginning of the 21st century. In this article some main aspects related to the economic activities of the overseas Chinese in Thailand during the indicated historical period are revealed.