Lactylation, a novel post-translational protein modification, is increasingly recognized for its widespread occurrence on lysine residues in both histone and non-histone proteins. Recent research has primarily focused on its implications in specific human diseases, particularly cancer progression, metabolic disorders, neurodegenerative diseases, and immune responses. However, it is crucial to acknowledge the significant roles played by viruses as pathogens in both clinical and veterinary medicine, as well as in zoological and phytopathological studies. This review highlights the latest advancements in understanding the mechanisms underlying lactylation and its regulation, emphasizing the role of lactylation in certain viruses. We discuss its involvement in essential biological functions, the pathogenic mechanisms of various viruses, host-virus interactions, and practical applications, including the potential for lactylation to serve as a therapeutic target in disease pathogenesis. Exploring the interactions between viruses and lactylation presents a promising research direction that may help refine the emerging concept of lactylation.