The bill was approved by a 68-28 vote in the Republican-dominated Tennessee House of Representatives. The state Senate passed the bill earlier this month.
Tennessee has seen heated debate over gun laws since last year’s school shooting in Nashville that killed three children and three adults.
Some House Democrats helped lead protests against the bill in the capital, leading to their brief expulsion from the legislature last year.
“This is a terrible day for Tennessee, our children, our teachers and our communities,” Justin Pearson, a Democrat who was voted out of the House last year and then re-elected, wrote on social media. “Instead of protecting children, they protected weapons again,” he said.
Republicans and other conservatives have often called for arming teachers in response to the numerous school shootings that have occurred in the US over the past 25 years.
Proponents of the measures argue that armed teachers deter potential school shooters. Opponents say guns in schools are likely to only lead to tragic accidental shootings.
About half of all states in the U.S. allow teachers or other school personnel to carry firearms on school grounds, according to the Giffords Law Center, a gun safety group.
Under Tennessee law, any person who wants to carry a concealed handgun at school must complete at least 40 hours of school police training. The cost of training, along with the firearm, is borne by the individual.
