In a 45-page ruling, Judge Timothy Black called Ohio's ban on recognizing out-of-state same-sex marriages "facially unconstitutional and unenforceable under any circumstances." Black noted his order does not require the state to allow gay unions be performed in the state.
State Attorney General Mike DeWine told Ohio Public Radio station WVXU that he will appeal the ruling.
DeWine told Ohio Public Radio on Monday that the ruling hasn't gone into effect yet, and that Black will decide soon whether to stay his order until the appeals process is finished.
Cleveland attorney Subodh Chandra told ideastream earlier this month that this is just the latest in a string of orders around the country chipping away at state bans on same-sex marriage.
"As we look down the road the great uncertainty is what is going to happen at the Sixth Circuit Court of Appeals or potentially beyond at the U.S. Supreme Court," Chandra said at the time. "Around the country every decision has gone in favor of the Constitution, and equal protection, and equality of opportunity, but we don’t know what the Sixth Circuit Court of Appeals is going to do, and it tends to lean conservative."
Ohio voters approved an amendment to the state constitution in 2004 banning same-sex marriage.