A novel 10-H hexagonal Bi(FeCr)O₃ (BFCO) perovskite nanosheet is synthesized by pulsed-laser ablation. Transmission electron microscopy (TEM) studies prove that the crystal structure of this phase is hexagonal-type with a P6₃/mmc space group. The atomic stacking sequence, revealed by high-resolution TEM, can be described as hhhcchhhcc in h–c notation. The magnetic properties of 10-H hexagonal BFCO perovskites are studied by both magnetic hysteresis loop measurements and first-principles calculations. The net magnetization of 10-H hexagonal BFCO comes from the anti-parallel spin moment of the Fe³⁺ and Cr³⁺ cations. The stability of the novel 10-H BFCO is also discussed by calculating its Goldschmidt factor and formation enthalpy. This work demonstrates the structural diversity in the Bi–Fe–Cr–O system, which may open the feasibility to explore the multi-functionality of this system.