Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder with a complex etiology, characterized by impairments in social interactions and communications, restricted interests, as well as repetitive and stereotypic behaviors. Clinical evidence has indicated that the gut microbiota in ASD patients varies from that in healthy individuals and participates in the pathogenesis of ASD. However, the underlying mechanism remains unclear. Recent studies have identified that the gut microbiota may indirectly contribute to the development of ASD through its metabolites. This review summarizes the relevance of two metabolites of gut microbiota, p-cresol and 4-ethylphenol, to ASD, along with their underlying pathogenic mechanisms. The aim is to explore the potential role of gut microbiota in ASD pathogenesis, providing new insights into the diagnosis and treatment of ASD.