Irvine's two goals helped Hull notch their first win of the season and avoid their worst start since 2006.
Having taken only a point from their opening three games, the mood was low at the Tigers but a double from the Socceroos midfielder and Fraizer Campbell's effort lifted spirits at the AESSEAL New York Stadium.
Rotherham, featuring fellow Aussie Ryan Williams starting on the right wing, opened the scoring after 10 minutes courtesy of a Richard Wood strike.
Irvine struck back for Hull 28 minutes in with a calm finish at the back post to level the scores at 1-1, before Campbell gave the Tigers the lead moments before the interval.
In the 47th minute, Irvine claimed his second for the night with a another composed finished to stretch Hull's lead to 3-1.
Rotherham struck back in the 75th minute to make for a nervy ending but Hull was able to hold on for victory.
The result was Hull CIty's first win of the Championship season and moves them to 16th on the ladder.
It was a tough night for Williams with the winger being substituted after 56 minutes.
It was also a difficult night at the office for Socceroos midfielder Massimo Luongo as his QPR side slumped to a 3-0 defeat at the hands of Bailey Wright's Bristol City.
It was QPR's fourth straight defeat with the side conceding 10 goals in their past two games, while the result was Bristol's first win of the campaign.
Matty Taylor put City ahead in the 41st before two second-half goals from Austrian Andreas Weimann as the pressure mounts on the west London side's ex-England manager Steve McClaren.
Luongo started the match but was substituted by Maclaren after 60 minutes.
Bailey Wright was not in the squad for Bristol City.
In League Two action, Socceroos great Harry Kewell's Crawley Town snatched a last gasp 2-2 draw with Swindon Town in a match which feature it's fair share of twists and turns.
Swindon were in charge in the first half racing to a 2-0 at the break.
However, Kewell's side fought back after a red card to Swindon's Toumani Diagouraga reduced the visitors to 10 men with Crawley scoring only moments later.
Swindon had another player sent off in the 53rd minute and Crawley pushed hard for an equaliser.
Deep into added time, Crawley had a player sent off but it wasn't going to stop them from completing an incredible comeback as they scored in the 99th minute to make it 2-2, with the final kick of the game.
Kewell's Crawley Town now move to 18th on the ladder after four games.
