Nikita Hand said the December 9, 2018, assault after a night of partying left her heavily bruised and suffering from post-traumatic stress disorder.
McGregor testified that he never forced the woman to do anything against her will and said she fabricated the allegations after the two had consensual sex. His lawyer had called Hand a gold digger.
The fighter, once the face of the Ultimate Fighting Championship but now past his prime, shook his head as the jury of eight women and four men returned the verdict after deliberating for about six hours in the High Court in Dublin.
He was mobbed by cameras as he left court but did not comment. He later said on the social platform X that he would appeal the verdict and the "modest award".
Hand's voice cracked and her hands trembled as she read a statement outside the courthouse, saying she would never forget what happened to her but would now be able to move on with her life.
She thanked her family, partner, friends, jurors, the judge and all the supporters that had reached out to her online, but particularly her daughter.
"She has given me so much strength and courage over the last six years throughout this nightmare to keep on pushing forward for justice," she said.
"I want to show (her) and every other girl and boy that you can stand up for yourself if something happens to you, no matter who the person is, and justice will be served."
The Associated Press generally does not name alleged victims of sexual violence unless they come forward publicly, as Hand has done. Under Irish law, she did not have the anonymity she would have been granted in a criminal proceeding and was named publicly throughout the trial.
Police investigated the woman's complaint but prosecutors declined to bring charges, saying there was insufficient evidence and a conviction was unlikely.
McGregor, in his post on X, said he was disappointed jurors didn't see all the evidence prosecutors had reviewed.
The jury ruled against Hand in a case she brought against one of McGregor's friends, James Lawrence, whom she accused of having sex with her in the hotel without consent.