Moon Jae-in from the South Korean Democratic Party on Wednesday became the new president of the Asian nation with support of 41.1 percent of voters, the NEC said.
About 13,4 million of South Korean nationals participated in the election, the NEC added, as cited by the Yonhap news agency.
A total of 13 hopefuls took part in the presidential race after two nominees had dropped out. Moon Jae-in of the liberal Democratic Party of Korea was considered as one of two main rivals along with and Ahn Cheol-soo of the center-left People's Party.
The vote took place less than two months after President Park Geun-hye was ousted following a corruption scandal that also led to her arrest.
The new president of South Korea will take office on May 10, immediately after the confirmation of the results by the NEC.
SPUTNIK/MNA