The N6-methyladenosine (mA) modification plays a critical role in cancer development. Little is known about the mA modification in triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer. Thus, the prognostic value of mA RNA methylation in TNBC deserves exploration. The expression levels of the 13 mA methylation regulators were compared between the 98 TNBC tumor samples and normal tissue samples based on the transcriptome profiles from The Cancer Genome Atlas (TCGA). The association between the mA regulators and patients' overall survival was assessed by Kaplan-Meier survival analysis and Cox regression analysis. Lasso regression analysis was conducted to construct a prognostic model based on the mA methylation system. The prognostic performance of the identified model was validated in GSE88847 and GSE135565 datasets. A nomogram combining the TNM stage and the mA prognostic model was further constructed for the survival prediction of TNBC patients. The mA regulator genes were remarkably dysregulated in TNBC tumor tissues, with , and significantly up-regulated and , and significantly down-regulated ( < 0.01). The expression level of was an independent unfavorable prognostic factor ( = 3.327, = 0.006), while ( = 0.425, = 0.009) was an independent favorable prognostic factor for TNBC patients. A prognostic model consisting of and was therefore proposed displaying higher accuracy of risk prediction when combined with TNM stage with an AUC of 0.791. The prognostic value of the identified signature remained consistent within the two external validation datasets. The mA methylation regulators were significantly dysregulated in TNBC tissues and could constitute a novel prognostic signature for the survival prediction of TNBC patients.