To find excellent materials for metal-ion batteries, we investigated the possibility of two-dimensional (2D) monolayer MBenes (CrB, FeB, MnB) as anode materials for Li, Na, K, Mg, and Ca ion batteries based on density-functional theory. The results show that the monolayer MBenes have small diffusion energy barriers, can maintain a stable average open-circuit voltage, and a theoretical storage capacity of up to 853 mA h g−1 in Li-ion batteries, superior to other ordinary anode materials. These properties suggest that monolayer CrB, FeB, and MnB are promising anode materials for metal ion batteries with good rate capacity.