The publication claims she "picked up a glass 'in a fit of rage' and threw it at McGregor" in the early hours of April 6.
McGregor allegedly sustained a 1cm cut to his lip and was take to a medical centre for treatment after reporting the incident to police.
WATCH: LILI REINHART AS A STRIPPER IN NEW FILM
Hollywood Showgirl's owner, Craig Duffy told the publication Ivy was fired on the spot.
"I know a conversation took place between the two of them, but I’m not privy to what was said – I don’t know if he said something wrong or she said something wrong," he explained.
"But regardless of what was said… we terminated the dancer immediately. She is banned from the club.
"People need to feel safe going into venues."
Mr Duffy said the club reached out to Mr McGregor, and hopes to see him back at the establishment.
"If he wants to come back, he's more than welcome."