The Republic of Korea has adopted a five-year, single-term presidential system since its constitutional amendment in 1987. Citizens over the age of 19 elect the president by direct vote. The 19th presidential election was held on May 9, 2017, following the Constitutional Court's citation of the 18th President's impeachment. The voter turnout rate for the election was 77.2%, 1.4% higher than the previous presidential election. Early voting was held in the presidential election for the first time, with 26.1% of the voters participating in the election. Approximately 220,000 overseas Koreans participated in the presidential election as a result of the new policy allowing voting by overseas residents.

 The Democratic Party of Korea's Moon Jae-in was elected the 19th president with a 41.1% vote. Other candidates received the following percentages of the vote: Liberty Korean Party’s Hong Jun-pyo (24.0%), People’s Party’s Ahn Cheol-soo (21.4%), Bareun Party’s Yoo Seung-min (6.8%), and Justice Party’s Sim Sang-jung (6.2%). The other eight candidates received only a few votes. According to the number of votes earned in the 17 metropolitan cities, provinces, and special autonomous city, Moon Jae-in won the popular vote in 14 districts, and Hong Jun-pyo received the most votes in three places: Daegu, Gyeongsangbuk-do, and Gyeongsangnam-do. According to the number of votes earned in the 250 –sis/guns/gus, Moon Jae-in received the most votes in 175 districts, and Hong Jun-pyo received the most votes in 75 districts.