The 41-year-old went all-out in an orange Alexander McQueen corset gown worth €2,790 which she paired with a gold Jimmy Choo bag that costs €795 and metallic Tom Ford heels, which she picked up for around €1,229.
She finished the outfit with a bespoke crown by Dublin designer Jennifer Kelly, of The Beaded Gem, who also designed Erin's white mesh gloves.
And her partner Terry Kavanagh was on photographer duties for the evening as she joked that it took "eight years of training" to get the perfect shot of her look.
Now in its 19th year, the Platinum VIP Style Awards saw Ireland's celebrities set take to the Marker Hotel in Dublin in their finest threads for the first time since 2019.
Among the 240 attendees were Muireann O'Connell, models Holly Carpenter and Thalia Heffernan, Miss Ireland Pamela Uba, RTÉ's Mary Kennedy, and Pippa O'Connor Ormond.
Una Healy turned heads in a striking satin teal cloak with Juliet sleeves by Irish designer Synan O'Mahony, before revealing that there was a whole other outfit underneath in the form of an electric purple dress with an embroidered bodice.
Una required the help of an assistant who was on hand to zhoosh up her outfit and fix her hair so that she looked picture perfect.
The Tipperary beauty admitted that she wanted to pull out all the stops for the most fashionable event of the year before she whisks her kids off to Disneyland Paris in two weeks' time.
"It's definitely dramatic. It's actually in two pieces so if I want to take it off later and have a little boogie, I can," she told the Sunday World.
Former Miss World Rosanna Davison stunned on the red carpet in a black and gold Paul Costelloe gown that she said was "inspired by the Book of Kells".
The mum-of-three scooped up the gong for Look of the Year and laughed that she's usually "elbow deep in baby s**t" and wearing "an old hoodie and leggings" so was caught off guard when her name was called out.
Westlife star Nicky Byrne made it just in time for the event with his wife Georgina after spending the day in Sligo rehearsing for Westlife's upcoming tour, which he said he was "so excited" to bring to Ireland and the UK next month.
Erin's turn at the star-studded event came as brother Conor launched a search for an Irish woman who defended him in a comedy sketch featuring Mike Tyson in an Instagram post that he later deleted.
The woman was asked who she thought would win in a fight, McGregor or Tyson, to which she said: "That's a difficult question… I don't know they both have the aggression… I'm going to have to go with Conor because he's Irish," she decides.
The camera man then says to the woman "alright, tell him," before she is startled by Mike Tyson appearing by her side.
Sharing a video of the skit, filmed for The Jimmy Kimmel show, McGregor said: "Who is this Proper Irish lady loyal to the backbone in the US can anyone tell me?"
"I wish to reach out and give a gift. That is how you do it! If you ever found yourself publicly going against your own," he said.