Seoul police planned to deploy more than 10,000 officers to monitor the rally near City Hall amid concerns of clashes.
Opponents and supporters of Park have divided the streets of Seoul in recent months with passionate rallies.
Park was jailed yesterday over allegations that she colluded with a confidante to extort money from businesses, take bribes and allow the friend to unlawfully interfere with state affairs.
Dozens of her supporters rallied outside the detention center yesterday, some of them crying and bowing toward the facility while vowing to "protect" her.
Park's presidential powers were suspended after lawmakers impeached her in December, following weeks of massive demonstrations by millions of people calling for her ouster.