PS James Harris, attached to the Brent MPS, was dismissed from the force without notice after it was found he had committed gross misconduct by assaulting the man whilst off-duty at the event in Hitchin on June 30 2018.
PS Harris was charged with one count of actual bodily harm following an investigation by Herts Police but the case was withdrawn by the Crown Prosecution Service.
Chief Superintendent Dan Knowles, in charge of policing at PS Harris’ North West Command Unit, said: “Police officers have to maintain the highest standards of behaviour on, and off, duty and headbutting someone is completely unacceptable.
“We need police officers who are calm and composed and help to de-escalate situations. It is clear that PS Harris lost control of himself on this occasion and has now paid the price of losing his job as a police officer.”
A misconduct hearing held on May 11 found the allegations proven at the level of gross misconduct and dismissed PS Harris without notice.
He will now be placed on the College of Policing (CoP) Barred List.