An investigation determined the drone dropped a package intended for an inmate on the north recreation yard, and it was thrown over a fence to the south recreation yard.
Two corrections officers called for assistance and ordered the inmates to stop fighting, according to the department.
They used pepper spray to control the fight.
About 75 inmates in the north recreation yard and 130 on the south recreation yard were strip-searched, run through a cell sensor and checked by a clinic.
The nine people involved in the fight were placed in solitary confinement. No staff members or inmates were injured, the department said.
Last year, the Mansfield post of the Ohio Highway Patrol increased efforts to watch and catch criminals who throw contraband over prison fences.