Penicillium caseifulvum is a fungus species of the genus of Penicillium which occurs on the surface of blue cheese and causes discoloration in form of brown spots.
While there exists a caseifulvum clade of gray-green cheese molds, this group is not distinguishable from Penicillium camemberti using a few microsatellite markers. It is commonly found on soft cheeses, being used to make Saint-Marcellin and Rigotte de Condrieu. Unlike its relatives also used in cheese-making, it does not produce cyclopiazonic acid due to a 2bp deletion in the CpaA gene. See Penicillium commune § Taxonomy for more information about its relatives.