N6-methyladenine RNA modification (m6A) is a RNA methylation modification catalyzed by methyltransferase at the 6th position nitrogen atom of adenine (A), which is the most common chemical modification of eukaryotic messenger RNA (mRNA). Recently, m6A has been found to play an important role in the dynamic regulation of RNA, which is crucial for some physiological and pathophysiological processes such as adipogenesis, cell differentiation, and the immune/inflammatory response. Metabolic diseases are a series of chronic inflammatory disorders caused by metabolic dysfunction of proteins, glucose, and lipids. Emerging studies have shown that m6A plays an important role in the process of metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVDs) via regulation of glucose/lipid metabolism and the immune/inflammatory response. In this review, we will summarize the role of m6A in metabolic diseases, which may provide new ideas for the prevention and treatment of metabolic diseases.