McGregor, 37, one of Ultimate Fighting Championship's most famous and bankable fighters, had denied the allegations of sexual battery following a 2023 Miami Heat game.
Lawyers for the woman, identified in the initial complaint as a 49-year-old Wall Street executive, filed a notice of voluntary dismissal at a Florida court on Tuesday.
Prosecutors had already declined to pursue criminal charges over the alleged incident.
McGregor attended the Miami Heat's NBA finals Game 4 clash with the Denver Nuggets in June 2023 as part of a sponsorship deal to promote a pain relief spray brand.
According to the initial lawsuit, McGregor met the anonymous woman at the end of the game in the venue's VIP section.
It alleges that an acquaintance of McGregor later led the woman to a men's restroom, where McGregor is accused of assaulting her in a toilet stall.
In a separate sexual assault case in Ireland last year, McGregor was found liable and ordered to pay around $250,000 in damages to a woman who accused him of rape.
Last month, the former UFC featherweight and lightweight champion was handed an 18-month suspension after missing three drug tests in a 12-month period.
Because the suspension was backdated to begin in September 2024, McGregor will be free to fight again by March next year - potentially leaving him free to fight at a UFC event scheduled to take place on June 14th at the White House to coincide with US President Donald Trump's birthday.
