In this study, 3D BiOBr@hollow carbon sphere (BiOBr@C) hybrids were synthesized via template-assisted hydrothermal methods. The effect of BiOBr@C on the catalytic decomposition of phenol was investigated. Compared with BiOBr, the BiOBr@C hybrid exhibited a significantly increased specific surface area. Furthermore, the BiOBr@C hybrid also showed improved visible-light absorption capacity because of the synergistic effect between the carbon spheres and BiOBr. Phenol decontamination experiments demonstrated that the BiOBr@C hybrid achieved an optimal catalytic decomposition efficiency of 34% within 24 h, outperforming both pure BiOBr and carbon spheres alone. Kinetic analysis indicated that the phenol decontamination process on BiOBr@C fit the Weber‒Morris intraparticle diffusion model, suggesting that the catalytic decomposition mechanism involved multiple processes, including intramolecular diffusion and surface chemical adsorption, rather than simple physical adsorption. This study provides a promising strategy for designing efficient BiOBr-based photocatalysts for phenol decontamination applications.