Following the establishment of the South Korean state in August 1948 , the current flag was declared official by the government of South Korea on October 15 , 1949 .
Flag had been used as the de facto national flag before then .
Following the establishment of the South Korean state in August 1948 , the current flag was declared official by the government of South Korea on October 15 , 1949 , although it had been used as the de facto national flag before then .