He said they were hopeful the court will rule in favor of same-sex marriage.
"One day, it's going to happen," he said. "You can't stop love."
About a dozen gay marriage opponents prayed the rosary outside the courthouse.
"I'm just praying for God's will to be done," said Jeff Parker, 53, from the Cincinnati suburb of Madeira.
Since the U.S. Supreme Court struck down part of the federal Defense of Marriage Act last year, gay marriage advocates have won more than 20 victories in federal courts. No decision has gone the other way in that time.
Two federal appeals courts have ruled in favor of gay marriage. On Tuesday, Utah appealed one of those rulings, asking the U.S. Supreme Court to take up the case and uphold its ban. Oklahoma followed suit a day later.