Millwall have been charged for homophobic chants aimed at Crystal Palace left-back Ben Chilwell during their FA Cup meeting last month.
Palace beat their south-east London rivals 3-1 in the fifth round last month in a match that was marred by Lions goalkeeper Liam Roberts' red card challenge on Jean-Philippe Mateta.
The Football Association said after the game it would investigate homophobic chants aimed at Chilwell, who is on loan at Selhurst Park from Chelsea.
Millwall have now been charged, external with misconduct and have until Wednesday to respond.