Frank spokesman Harry Gural said in a statement about 300 friends, family and colleagues were on hand for the 6:30 p.m. wedding outside a Marriott hotel, The Boston Globe reported.
"I'm thrilled for him," U.S. Rep. James P. McGovern, D-Mass., said. "Massachusetts has always led the way, but Barney has been out front on civil rights issues for a while."
Frank, 72, has served in Congress since 1981. He was one of the first openly gay politicians in national office.
Ready, 42, of Ogunquit, Maine, works as a photographer and runs a business that does custom awnings, carpentry, painting, welding and other services, Gural said in the statement.
Also attending was U.S. Rep. Al Green, D-Texas, who served with Frank on the House Financial Services Committee.
"He's a wonderful person," Green said. "[Frank] is one of the most brilliant persons I've ever known."
The newspaper said President Barack Obama was not invited because Frank did not want the Secret Service presence to inconvenience the town or his guests.