Barnsley have been fined £20,000 and ordered to "implement an action plan" after Stoke midfielder James McClean was the target of sectarian abuse at Oakwell.
The sanction relates to chants heard during the Sky Bet Championship clash between the sides on November 9, which the Potters won 4-2.
Derry-born McClean has repeatedly faced criticism for his decision not to wear a poppy on his shirt in the game closest to Remembrance Day.
The 30-year-old has said that decision was taken out of respect for those who died in the city on Bloody Sunday in 1972.
The Football Association charged Barnsley with a breach of rule E20 and says the club "admitted failing to ensure that its spectators, and all persons purporting to be its supporters or followers, conducted themselves in an orderly fashion and refrained from using abusive and/or insulting words which included a reference, whether express or implied, to nationality and/or religion and/or beliefs while attending the fixture."
In a statement, the club said: "Barnsley Football Club has a zero-tolerance policy on any form of discrimination and, as such, are immensely disappointed to have been found guilty of violating FA rulings.
"The club will act upon the case findings and will continue to work closely with the FA and Kick It Out. Anybody found to be involved in any form of discriminatory behaviour when representing Barnsley Football Club face a potential ban from attending matches."