This review provides an overview of the enzymes involved in the degradation of plant cell wall polysaccharides by *Aspergillus* species, along with the genes encoding these enzymes and the regulation of their expression. The plant cell wall polysaccharides, including cellulose, hemicellulose (xylan, galacto(gluco)mannan), and pectin, are discussed in detail, highlighting their structural features and the role of aromatic residues in their cross-linking with lignin. The biodegradation of these polysaccharides by *Aspergillus* is achieved through various classes of enzymes, such as endoglucanases, exoglucanases, β-glucosidases, endoxylanases, β-xylosidases, β-mannanases, β-mannosidases, polygalacturonases, pectin lyases, rhamnogalacturonan lyases, α-galactosidases, β-galactosidases, endogalactanases, exogalactanases, α-glucuronidases, feruloyl and p-coumaroyl esterases, acetyl- and methylesterases. The regulation of gene expression in *Aspergillus* is also discussed, focusing on the coordinated expression of genes encoding xylanolytic and cellulolytic enzymes. The industrial applications of these enzymes in the food and feed industries are highlighted, along with the potential for heterologous protein production in *Aspergillus*. The review concludes with a discussion of the current knowledge and future directions in the field.This review provides an overview of the enzymes involved in the degradation of plant cell wall polysaccharides by *Aspergillus* species, along with the genes encoding these enzymes and the regulation of their expression. The plant cell wall polysaccharides, including cellulose, hemicellulose (xylan, galacto(gluco)mannan), and pectin, are discussed in detail, highlighting their structural features and the role of aromatic residues in their cross-linking with lignin. The biodegradation of these polysaccharides by *Aspergillus* is achieved through various classes of enzymes, such as endoglucanases, exoglucanases, β-glucosidases, endoxylanases, β-xylosidases, β-mannanases, β-mannosidases, polygalacturonases, pectin lyases, rhamnogalacturonan lyases, α-galactosidases, β-galactosidases, endogalactanases, exogalactanases, α-glucuronidases, feruloyl and p-coumaroyl esterases, acetyl- and methylesterases. The regulation of gene expression in *Aspergillus* is also discussed, focusing on the coordinated expression of genes encoding xylanolytic and cellulolytic enzymes. The industrial applications of these enzymes in the food and feed industries are highlighted, along with the potential for heterologous protein production in *Aspergillus*. The review concludes with a discussion of the current knowledge and future directions in the field.