McCulloch completed his treble inside the first half, which included two penalties, as the runaway leaders secured the title with eight games to spare.
Gers manager Ally McCoist had steered his side to a second straight promotion and McCulloch, a reliable performer during some troubled times, was a fitting hero at Ibrox.
The party planning started in the third minute as Grant Adam's mistimed lunge on Andrew Little was punished by McCulloch's fierce penalty.
Airdrie were doing little to spoil the mood and Jon Daly sent a header wide before the Gers received a second spot-kick.
Gregor Buchanan brought down Andrew Templeton in the box and the nerveless McCulloch (21) calmly slotted the ball past Adam.
Captain McCulloch was leading his side to promotion and the veteran completed his treble with a composed finish (41) after being picked out by Nicky Law.
Only desperate defending denied McCulloch a second-half fourth, his shot striking an opponent, and Lee Wallace then drove the ball into Adam's legs.
Bilel Mohsni lashed against the post before dragging the rebound wide as Rangers failed to relent, but home keeper Cammy Bell had some brief work when he smothered James Lister's shot.
Substitute Nicky Clark sent a late drive inches past the post, but the hosts had done enough and could toast an unbeaten run to the title.