The polling will begin at 6:00 a.m. local time and will end at 6:00 p.m.
More than 44.3 million eligible voters will elect 17 metropolitan mayors and provincial governors, 226 lower-level council heads, 779 members for provincial and metropolitan councils, and 2,602 members for the lower-level local councils, according to Yonhap News Agency.
There will also be by-elections taking place on seven vacant seats of the National Assembly.
Two former presidential candidates Lee Jae-myung and Ahn Cheol-soo are also running in the by-elections.
A tough contest is expected between the ruling People Power Party and the main opposition Democratic Party (DP).
Source: Anadolu Agency