The lawsuit says Mueller was falsely accused by one of Swift's security team of grabbing the singer's buttocks backstage at the Pepsi Center on June 2, 2013.
It says Mueller was fired two days later from his job at KYGO radio.
Taylor Swift and Jimmy Fallon Among Early Emmy Winners
The lawsuit says Mueller denies inappropriate contact with Swift and noted that he had met many other celebrities without incident.
A statement from Swift's publicist on Saturday says Mueller's employer was given evidence after the incident and made its own decision on his job status.