The striker, 29, who was brought to the club by Andy Scott in 2011, has been an integral part of the Millers' promotion push this season and has been rewarded with an extended stay.
"I'm delighted to get the chance to stay at the club for another two years," Revell told the club's official website.
"It was a no-brainer due to what's happening at the club with it being an exciting time. I've had great support while I've been here and I'm obviously delighted to get the chance to extend my stay here."
Boss Steve Evans, who has picked the target man 44 times this campaign, said: "I'm absolutely delighted that Alex has agreed to extend his time with us. Since I arrived the lad has been outstanding.
"His performances have seen many clubs register an interest but within minutes of making it clear I wanted him part of our future, the lad wanted to sign to stay with the Millers."
- Sports & Recreation