Dennis Wise enjoyed a third straight win since becoming Swindon boss thanks to Alan Goodall's bizarre own goal.
Rochdale keeper Matt Gilks was helpless as Goodall headed in from close range on the stroke of half-time.
Gilks prevented a more emphatic win for Swindon by saving two penalties in the second half, firstly from Christian Roberts and then from Paul Evans.
Rochdale failed to find any rhythm and all they could muster in the second half was a shot by Adam Rundle.