Protesters have been calling for Park to resign since revelations last week that her confidante and spiritual adviser Choi Soon-sil may have seen secret government documents and influenced policy.
New positions
In an apparent attempt to stem the scandal Wednesday, Park named three new senior officials to her cabinet.
Kim Byong-joon, a professor at Seoul's Kookmin University, will replace Hwang Kyo-ahn as prime minister, the president's office confirmed to CNN.