Findlay High School was placed on lockdown on Wednesday.
The school district said the lockdown was initiated after the school received what was later determined to be an unsubstantiated threat.
The school district said they immediately contacted the police department to investigate.
The lockdown began around 1 p.m. and, out of an abundance of caution, lasted until dismissal at 2:40 p.m.
“The safety of students and staff continues to be a top priority for the district,” the school district said in an e-mail to the community.
“We appreciate our strong partnership with the Findlay Police Department as they teamed closely with us to navigate this situation.”