The Mathews Bridge reopened Tuesday afternoon just before 3 p.m. after it had been closed down in both directions while police investigated a suspicious item.
The package was found to be "nothing of concern," Jacksonville police said.
Traffic into and out of Downtown was briefly rerouted over the Hart Bridge.
"Thank you for your patience as we make safety a priority for everyone," the Sheriff's Office posted in a Tweet.
A spokeswoman for Duval County Public Schools said the timing of the bridge closure this afternoon could cause delays in some normal bus routes.
"School staff will remain with students who are awaiting bus transportation. We appreciate your patience and will continue to provide updates as needed," DCPS said in an alert to parents.