The supporter who ran on to the pitch during last week's Champions League match against Manchester United at Parkhead, has cost the club a £42,430 fine. Part of the fine was imposed by Uefa for the late start to the game which ended in a 1-1 draw.
Celtic said: "We accept the judgement and there will be no appeal."
A statement on UEFA's official website read: "Celtic FC have been fined 50,000 euros by UEFA for the improper conduct of their supporters at last week's UEFA Champions League Group E match against Manchester United FC in Glasgow.
"The UEFA Control and Disciplinary Body handed down the fine to the Scottish club in relation to a pitch invasion by a spectator and a late kick-off at the match, which ended in a 1-1 draw.
"An appeal may be lodged within three days of receipt of the grounds for the decision."