Due to its unique in‐plane anisotropic structure, high carrier mobility, and adjustable direct bandgap, 2D black phosphorus (BP) has emerged as an important graphene‐like material for various micro‐ and optoelectronic, energy, catalytic, and biomedical applications. However, its lack of environmental stability severely limits its processing in ambient conditions. Chemical functionalization is an effective method for increasing the ambient stability of the material. Herein, the main approaches for chemical functionalization of 2D BP with various organic and inorganic substrates, as well as the routes for the preparation of 0D/2D and 2D/2D heterostructures, are discussed. Furthermore, the recent advances of 2D BP‐based materials in energy and catalysis fields are summarized. Finally, the challenges and future prospects for the preparation and functionalization of 2D BP are also highlighted.