The prolific Scotland striker has made a big impact at Ewood Park since making an £8 million move from Huddersfield Town two years ago, scoring 28 goals in his first season with the club and a further 25 in the 2013-14 campaign.
Rovers have rewarded the 24-year-old with a new deal that will run until 2019 and Rhodes is happy to have committed his future to the club.
He told Blackburn's official website: "I'm delighted, I'm very happy.
"It is a fantastic football club and I'm very lucky to be here.
"I enjoy coming in every day and to have an extension of two more years on top of my current contract is a real bonus.
"I was delighted to sign it, it is a club I enjoy playing for. The fans have been great ever since I've come in the place and I've just thoroughly enjoyed it so I'm delighted to be here."
Gary Bowyer's side will be looking to improve on last season's eighth-placed finish when they kick off the new campaign with the visit of relegated Cardiff City on August 8.