Monoamine oxidase (MAO) is a membrane‐bound mitochondrial enzyme that maintains the steady state of neurotransmitters and other biogenic amines in biological systems through catalytic oxidation and deamination. MAO dysfunction is closely related to human neurological and psychiatric diseases and cancers. However, little is known about the relationship between MAO and viral infections in humans. This review summarises current research on how viral infections participate in the occurrence and development of human diseases through MAO. The viruses discussed in this review include hepatitis C virus, dengue virus, severe acute respiratory syndrome coronavirus 2, human immunodeficiency virus, Japanese encephalitis virus, Epstein‐Barr virus, and human papillomavirus. This review also describes the effects of MAO inhibitors such as phenelzine, clorgyline, selegiline, M‐30, and isatin on viral infectious diseases. This information will not only help us to better understand the role of MAO in the pathogenesis of viruses but will also provide new insights into the treatment and diagnosis of these viral diseases.