Class III plant peroxidases (Prxs) are key enzymes in plant defence reactions, involved in various physiological processes such as lignin and suberin formation, cell wall cross-linking, and phytoalexin synthesis. They are also involved in the metabolism of reactive oxygen species (ROS) and reactive nitrogen species (RNS), playing a central role in host plant defences against necrotrophic and biotrophic pathogens. Prxs are induced during plant defence responses and are involved in the reinforcement of cell walls, the production of antimicrobial metabolites, and the generation of ROS and RNS. They are regulated by signalling pathways involving salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), which are involved in different defence responses against pathogens. Prxs are also involved in the production of phytoalexins, which are antimicrobial compounds. The review discusses the role of Prxs in plant defence reactions, their involvement in the metabolism of ROS and RNS, and their regulation by signalling pathways. It also highlights the importance of Prxs in the reinforcement of cell walls and the production of antimicrobial metabolites. The review concludes with a discussion of the signalling pathways that regulate Prx gene expression during plant defence.Class III plant peroxidases (Prxs) are key enzymes in plant defence reactions, involved in various physiological processes such as lignin and suberin formation, cell wall cross-linking, and phytoalexin synthesis. They are also involved in the metabolism of reactive oxygen species (ROS) and reactive nitrogen species (RNS), playing a central role in host plant defences against necrotrophic and biotrophic pathogens. Prxs are induced during plant defence responses and are involved in the reinforcement of cell walls, the production of antimicrobial metabolites, and the generation of ROS and RNS. They are regulated by signalling pathways involving salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), which are involved in different defence responses against pathogens. Prxs are also involved in the production of phytoalexins, which are antimicrobial compounds. The review discusses the role of Prxs in plant defence reactions, their involvement in the metabolism of ROS and RNS, and their regulation by signalling pathways. It also highlights the importance of Prxs in the reinforcement of cell walls and the production of antimicrobial metabolites. The review concludes with a discussion of the signalling pathways that regulate Prx gene expression during plant defence.