Taking to Facebook, the singer shared her disappointment after being told to leave the private lounge on Monday.
"Disappointed to be evicted from the Qantas Lounge after being a member since 1990 for wearing 'inappropriate footwear'? hahaha (new rules)," she posted along with a snap of her outfit, showing off a pair of strappy sandals.
The iconic singer was travelling to Brisbane ahead of her appearance at the Caloundra Music Festival and decided to wear appropriate footwear to accommodate for the heat.
An employee working at the lounge told Daily Mail Australia they were unhappy to ask the 48-year-old to leave but were adamant that no exceptions would be made for her celebrity status.
The Qantas lounge is known for their strict dress code, advising that thongs, gym wear, board-shorts, Ugg boots, revealing, unclean and torn clothing are not permitted.
"We completely understand that being declined at the door isn't a great experience, so this is a good opportunity to remind those wanting to use our capital city lounges of the dress code that applies," a Qantas spokesman told Fairfax Media.
"We've always had smart casual dress standards for our lounges, which are similar for those in place for most clubs and restaurants. Over the past year or so, we had clear feedback from lounge members that they wanted these existing guidelines to be applied more rigorously.
"We reached out to members earlier this year to remind them of the dress standards and had a grace period up until April this year."
The mum-of-one recently caused a stir after performing the national anthem at the AFL grand final on Saturday.
Belting out Advance Australia Fair in front of 100,000 people at the MCG and the millions of Australians watching on TV, in a blunder, Kate messed up the last line of the song.
She was heard singing: "In history's stage, let every state Advance Australia Fair" instead of: "In history's page, let every stage Advance Australia Fair".
Nerves aside, Kate still delivered a powerful performance!