"I won't do it again," he said.
Anna Miller, 33, married to a Mullet nephew and mother of six, also apologized, turning to relatives of victims as she said, "I'm sorry, it won't happen again." Like most of the women, she was sentenced to one year.
Federal prosecutor Bridget Brennan urged the judge to punish Mullet adequately.
"He is a danger to this community," she said. "He is capable of controlling 15 defendants."
Brennan repeated key testimony against Mullet and said he has remained the leader of his eastern Ohio community despite being locked up since his arrest in late 2011.
U.S. Attorney Steven Dettelbach, whose office directed the prosecution, said he was confident the law would withstand a constitutional challenge.
As for Mullet, "I think the sentence he got was harsh; I think it was appropriately harsh," Dettelbach said. "Mr. Mullet's conduct in court today reiterated yet again his utter failure to respect the rule of law and his utter lack of remorse."
The jury had sided with prosecutors' arguments that the defendants should be found guilty of a hate crime because the attacks were brought about by religious differences.
The judge said the defendants have two weeks to file appeals of their sentences or convictions. Defense attorneys have indicated such appeals are likely.
Rhonda Kotnik, attorney for Kathryn Miller, a 24-year-old mother of three who received a one-year sentence, said appeals would focus on whether the hate-crimes law is unconstitutionally broad and whether restraining the victims to cut their beards amounted to kidnapping.
"There are lots of issues," she said.
Nine of 10 men who were convicted have been locked up awaiting sentencing. The six women, who all have children, have been free on bond.