Abstract: N⁶-methyladenosine (m⁶A) is the most prevalent post-transcriptional RNA modification in eukaryotic cells. m⁶A methyltransferase complexes and demethylases are involved in the dynamic and reversible regulation of m⁶A modification, while m⁶A binding proteins could specifically identify m⁶A modification and regulate RNA metabolism, including splicing, translocation, stability, and translation. m⁶A is found to play a vital role in all the fundamental biological processes, including the regulation of the immune system, from normal development to diseases. The normal development and functioning of the immune system rely on the precise regulation of the relevant gene expression, and m⁶A modification is crucial to the regulation. Herein, we reviewed the concept, the functions, and the mechanism of m⁶A modification, concentrating on its role in immune system function modulation. Furthermore, we highlighted present obstacles and future research directions in the field, intending to provide a theoretical foundation and reference for future study on how m⁶A modification is involved in immune regulation.