[6] Originally located in Samseong-dong, Seoul, KEPCO headquarters was relocated to the city of Naju in South Jeolla Province in August 2014 as part of a government decentralization program.

KEPCO traces its origins to Hanseong Jeongi Hoesa (Seoul Electric Company), founded in 1898 during the Korean Empire.

Subsequently, American business Henry Collbran and Harry Rice Bostwick were contracted to manage Seoul's streetcars, lights, and telephone systems.

By the end of that year, the company had succeeded in launching its streetcar service, and soon after had turned on its first electric lights in Seoul’s Jongno Street.

Claiming it broke the mortgage contract, Collbran responded in demand for the repayment of debts related to the railroad construction project and pressed on profits.

Gojong mutually withdrew all demands between the two sides, and in February 1904 established Hanmi Electric Company (韓美電氣會社) to hand over all rights and assets.

[28] KEPCO's overseas forays started in 1993 when the company was awarded a technical consulting contract for maintenance on the Guangdong nuclear power plant in China.

In the area of transmission and distribution consultation, KEPCO has undertaken projects in Myanmar, Cambodia, Vietnam, Indonesia, Libya, Ukraine, Paraguay and Egypt.

In 2010, a KEPCO-led consortium including Samsung C&T and Korean firm Techint was awarded a contract to build and operate the Norte II combined cycle gas power plant in the Mexican state of Chihuahua.

[32] In order to raise its fuel self-sufficiency rate to 60% by 2020,[33] in 2010, KEPCO acquired the Bylong Coal Mine in Australia from Anglo American PLC.

[34] Also in 2010, KEPCO bought a 20% stake in Bayan Resources in Indonesia, thus allowing the company to raise its coal self-sufficiency rate by 7 million tons annually from 2015.

[37] In early 2010, KEPCO announced it would invest over US$7 billion in its smart grid business by 2030 to make electricity distribution more efficient and decrease Korea's greenhouse gas emissions.

[39] In June 2011, it was announced that KEPCO would collaborate with IBM to build a Total Operations Center at the Jeju Smart Grid Test-Bed Demonstration Complex.