Barcelona were also banned from selling tickets to their supporters for their next away European game, although that punishment is suspended for a year.
Barca lost the tie 6-4 on aggregate after PSG won Tuesday's second leg 4-1.
On April 10th, Paris police said they had questioned two people after videos were published on social media of a supporter making monkey noises and another making Nazi salutes at the Parc des Princes.
"The UEFA Appeals Body has decided to fine FC Barcelona 25,000 euros and to ban FC Barcelona from selling tickets to its away supporters for its next UEFA competition match, for the racist behaviour of its supporters," UEFA said.
"Said ban from selling tickets to its away supporters is suspended for a probationary period of one year, starting from the date of the present decision."
