The club beat their League One rivals Shrewsbury Town yesterday 2-1 after extra time at Wembley to secure a place in the Championship next season.
The Millers will celebrate their victory in style with a parade around the town tomorrow evening.
The Mayor of Rotherham, councillor Alan Buckley, will join the players on the bus while Rother FM will host the event from 5.30pm in All Saints' Square.
Coun Buckley said: "Rotherham had a well-deserved victory as the whole team played well. I wish the club all the best for next season in the Championship."
Coun Chris Read, leader of Rotherham Council, said he was proud to be present at such a fantastic occasion.
He added: "I want to say massive congratulations to the team. This is fantastic for the people of Rotherham and coming on the back of other recent successes, the 10k, Tour de Yorkshire, and the UEFA under 17s competition, we’ve had a great few weeks of sport.
"Roll on next season.”
“This is not only a fantastic occasion for the football club, but a celebration for everyone connected with Rotherham.
“We have enjoyed similar occasions in the past which have always been well attended, and everyone at the club is looking forward to thanking our loyal fans for their wonderful support and seeing a sea of red and white across the town centre.”