3d-transition metal (Fe, Co, Ni, and Mn)-based MXene materials have been predicted to demonstrate exceptional electrochemical performance because of their good electrical conductivity and the presence of metallic atoms with multiple charge states. However, until now, there have been no reports on MXenes based on Fe, Co, Ni, and Mn, due to the lack of 3d-metal-layered precursors. Herein, we successfully synthesized the first 3d-transition metal-based MXenes, Mn₂CT_x by exfoliating a layered precursor derived from the anti-perovskite bulk Mn₃GaC. The as-prepared Mn₂CT_x MXene nanosheets were employed as anode materials in lithium-ion batteries, which exhibited stable storage capacity of 764.7 mAh·g⁻¹ at 0.5 C, placing its storage capacities at an upper-middle level compared with other reported MXene materials as well as other Mn-based anode materials. Overall, this study opens a new avenue for MXene research by synthesizing 3d-transition metal-based MXenes for electrochemical applications.