N 6-methyladenosine (m 6 A), the most abundant modification in eukaryotic cells, regulates RNA transcription, processing, splicing, degradation, and translation. Circular RNA (circRNA) is a class of covalently closed RNA molecules characterized by universality, diversity, stability and conservatism of evolution. Accumulating evidence shows that both m 6 A modification and circRNAs participate in the pathogenesis of multiple diseases, such as cancers, neurological diseases, autoimmune diseases, and infertility. Recently, m 6 A modification has been identified for its enrichment and vital biological functions in regulating circRNAs. In this review, we summarize the role of m 6 A modification in the regulation and function of circRNAs. Moreover, we discuss the potential applications and possible future directions in the field.