School Superintendent Art Johnson said the district has not received any specific threats.
But he said he and Police Chief Jim Kelly believes the district should beware of the prospect for schools becoming "soft targets" for terrorists, the Palm Beach Post reported.
"We are simply listening to the same news everyone else is listening to and what we've heard is the possibility of people trying to disrupt our election process," Johnson said.
Nearly half the district's schools are polling sites.
All doors will be locked during classes, teachers will escort students to restrooms or other locations. Staff will monitor halls during class changes.
Officials said they expect parents will be more relieved than worried when they are told about the stepped up security.