When Was South Korea Founded?

South Korea, officially the Republic of Korea, was formally established on 15 August 1948. This date marks the inauguration of the First Republic and the beginning of sovereign governance on the southern half of the Korean Peninsula after the end of Japanese colonial rule and the post‑World War II division of Korea¹².

Constitution and First Government

• The constitution of the Republic of Korea was promulgated on 17 July 1948⁸.
• The new constitution took effect on 15 August 1948, the day the first government was inaugurated and the Republic officially came into being¹².

First President and the First Republic

• Syngman Rhee became the first President of South Korea, assuming office on the founding day, 15 August 1948¹².
• This period is referred to as the First Republic of South Korea, lasting until 1960.

Historical Context

• After Japan’s surrender in 1945, Korea was divided along the 38th parallel, with the United States administering the south and the Soviet Union the north.
• The establishment of the Republic of Korea in 1948 solidified a separate, democratic state in the southern part of the peninsula, while the Democratic People’s Republic of Korea (North Korea) was founded the following year.

Key takeaway: The founding of South Korea on 15 August 1948 signified the birth of an independent, democratic nation under President Syngman Rhee, anchored by a constitution adopted earlier that July.