President Park Geun-hye will likely announce her pick to fill the vacant prime minister seat as early as this Monday.
With the local elections out of the way, the president is expected to speed up the Cabinet reshuffle in response to public criticism of the government's lax handling of April's ferry disaster.
Sources say President Park has been searching for a candidate with an innovative mind and ethical integrity.
This comes after her previous Prime Minister nominee Ahn Dai-hee withdrew last month amid criticism over the amount of money he earned in the private sector after retiring as a Supreme Court justice.
"I'm looking for a qualified person that the citizens want to lead the national reform."
The president has been mulling over potential candidates, as she seeks to press ahead with her reform agenda.
Among the candidates under consideration are Kim Young-ran, former head of the Anti-Corruption and Civil Rights Commission, as well as Cho Moo-je, a former Supreme Court justice.
With the ruling Saenuri Party failing to grab winning tickets from the Chungcheong-do Provinces at the local elections, candidates from these provinces are also being considered, including Sim Dae-pyeong, the chairman of the presidential committee on local autonomy development.
A reshuffle is also imminent at the presidential office.
President Park on Sunday tapped Yoon Doo-hyun as the new senior presidential press secretary after a close aide stepped down from the post as he's reportedly considering running in a by-election next month.
Yoon, the head of YTN Plus, a digital contents provider, was noted by the presidential office for his balanced way of thinking and sharp analytical skills as a journalist.
"Yoon was appointed as he's the right person to explain government reform policies to the public, and receive their understanding and cooperation."
A review process is also underway for other presidential aides to be replaced.
Kim Min-ji, Arirang News.