The 2D materials with both ferromagnetism and semiconducting properties are desirable for spintronics applications. Here, inspired by the successful synthesis of single‐layer CoCl
, it predicts that Janus single‐layer CoClBr is a 2D intrinsic ferromagnetic semiconductor with a direct bandgap of 3.71 eV by first‐principles calculations. Single‐layer CoClBr exhibits an in‐plane magnetic anisotropic...