The RNA-binding protein HNRNPA2B1 is identified as a nuclear "reader" of the m6A mark, acting as an adaptor that recruits the Microprocessor complex to a subset of precursor miRNAs, facilitating their processing into mature miRNAs. HNRNPA2B1 binds m6A-containing sites and the RGAC motif in nuclear transcripts, and its depletion causes similar changes in alternative splicing to those observed with METTL3 depletion, the m6A writer. HNRNPA2B1 interacts with the Microprocessor complex protein DGCR8, promotes the processing of METTL3-dependent pri-miRNAs, and regulates a subset of m6A-dependent miRNAs. These findings suggest that HNRNPA2B1 mediates the effects of m6A on primary microRNA processing and alternative splicing.The RNA-binding protein HNRNPA2B1 is identified as a nuclear "reader" of the m6A mark, acting as an adaptor that recruits the Microprocessor complex to a subset of precursor miRNAs, facilitating their processing into mature miRNAs. HNRNPA2B1 binds m6A-containing sites and the RGAC motif in nuclear transcripts, and its depletion causes similar changes in alternative splicing to those observed with METTL3 depletion, the m6A writer. HNRNPA2B1 interacts with the Microprocessor complex protein DGCR8, promotes the processing of METTL3-dependent pri-miRNAs, and regulates a subset of m6A-dependent miRNAs. These findings suggest that HNRNPA2B1 mediates the effects of m6A on primary microRNA processing and alternative splicing.