"Because of the data we now have, we’re changing our guidance and are no longer recommending that students who have been exposed to another COVID+ student quarantine – as long as all students have been wearing masks and the exposure took place in a classroom setting," DeWine tweeted Wednesday afternoon.
He added, however, that students should still quarantine if they failed to maintain mask or social distancing guidelines.
"Ultimately, this is one more step to keep our kids in the classroom – which is where we want them to be," he said.
Proponents of reopening schools amid the pandemic have argued that keeping children at home is bad for their mental health, and multiple studies have supported that notion.
One, from the California Partners Project, found that shutdowns were leaving teenagers struggling under social isolation and increased screentime.
Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, said earlier this month that schools are not a major source of coronavirus transmission and has been advocating more reopenings.
"We now have substantial data that shows that schools’ face-to-face learning can be conducted in K-12, and particularly in the elementary and middle schools in a safe and responsible way," he said, adding that teachers and students were more likely to contract the virus outside of the classroom.
He also noted that in-person learning has positive effects on mental health and grants low-income students access to food programs.
And members of both parties were increasingly receptive to the idea of reopening schools.
President-elect Joe Biden said during a conference call with governors that schools should reopen within his first 100 days in office as part of his coronavirus plan.
And outgoing Education Secretary Betsy DeVos told Fox News earlier this month that prolonged closures are having "tragic" effects on children.
"The conclusion is schools have got to reopen, particularly for the kids who are most vulnerable," she told "America’s Newsroom."
"We see it being done safely and without incident or minimal incident across the country," she later added. "We are going to have a lost generation if we don't heed that continued warning."
Fox New's David Rutz and Kayla Rivas contributed to this report.