The Uruguayan forward was charged by police after he barged into an officer while celebrating Pep Biel's 85th minute goal in a 3-1 win over the Scottish side in the second leg of their round-of-32 tie on Feb. 27.
The policeman was looking to prevent Santos from getting any closer to away fans at Celtic Park and a Copenhagen steward was also charged with an offence by police as tempers flared.
"The Control, Ethics and Disciplinary Body has decided to suspend. Santos for a total of three UEFA club competition matches for which he would be otherwise eligible," UEFA said in a statement.
Copenhagen, who defeated Celtic 4-2 on aggregate, lost 1-0 in the first leg of their round-of-16 tie at Istanbul Basaksehir last month before the coronavirus pandemic forced the suspension of the competition.