Swindon's Mark Cooper was disappointed to have lost the final game of the season against Rotherham but was delighted to have finished eighth.
Wes Thomas fired Rotherham into a first-minute lead and then doubled the visitors' advantage midway through the opening period - the influential Ben Pringle setting up both the goals.
The Millers enjoyed a stroll in the Wiltshire sunshine, going 2-0 ahead, but Swindon put them under the cosh in a 15-minute second-half window, clawing a goal back from a Michael Smith penalty.
"It's given us a lot to look forward to for next season. We've got a lot of exciting young players here and the experience they've gained will be invaluable in their development," said Cooper after the 2-1 loss.
"We've had a terrific run of late and it's given us plenty of encouragement for the future."