Pyrotechnics were on display as supporters group The Green Brigade unfurled a Muhammad Ali-inspired display in the home end.
It read: “Ain’t nothing wrong with going down. It’s staying down that’s wrong.”
“Setting off fireworks” is a breach of Uefa disciplinary regulations and the Parkhead club were hit with a charge earlier this month.
It’s the second time this season where Celtic have been found guilty and fined by the governing body over supporter behaviour. The previous incident occurred in the Europa League play-off encounter away to AIK.
The day after they were hit with the latest charge, Celtic’s board released a statement where they condemned the supporters responsible.
It said: “Following the latest UEFA charge against the club for the use of fireworks at Celtic Park, it is with real disappointment and frustration that the club needs to appeal again for this behaviour to stop.
“UEFA’s stance on the issue of pyrotechnics is unequivocal and very well-known.
“The club has been sanctioned on numerous occasions and yet, very disappointingly, this behaviour by a small minority persists. In addition, the numerous financial penalties placed on Celtic continue to come out the pockets of supporters who invest in the club.
“The club does not want it, our supporters do not want it and UEFA will continue to punish the club whenever it occurs as it is a clear breach of their regulations.
“Given the number of repeated offences, we should also be very aware that there could be further, very serious repercussions which could have hugely detrimental consequences for the club and our supporters.”