The striker, who has put pen-to-paper on a one-year deal, was a regular starter in manager Mark Robins' side this season, scoring nine goals.
Broughton said: "I'm delighted with the new deal. I've felt at home in Rotherham and can see the club is moving forward and I want to be a part of that.
"It's been a great season for the club. Rotherham United are now a team that is taken seriously around the country and we will now start the new campaign on zero points, which will give us a level playing field with the rest of the division."