Freddie Sears put Town in front in the third minute but Danny Ward equalised for Rotherham only four minutes later with the scoreline remaining 1-1 at the break.
Second-in-the-table Town face familiar foes Plymouth Argyle on Saturday as they aim to maintain their extraordinary start to life back in the Championship.
Boss Mick McCarthy says the Blues need to stick together as they look to end a run which has seen them win just once in their last eight league games. On Saturday, Town visit Nottingham Forest, another side currently going through a difficult spell.