Cubic monodisperse BaCeF5 and BaCeF5:Tb3+ nanocrystals have been successfully synthesized by a citric acid assisted solvothermal method. The crystalline phase, size, morphology, and luminescence properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL), photoluminescent excitation spectra (PLE) as well as dynamics decay. The results reveal that the Tb3+-doped BaCeF5 sample shows a strong green emission centered at 546 nm, corresponding to the 5D4→7F5 transition of Tb3+ due to an efficient energy transfer from Ce3+ to Tb3+. The decay lifetime of Ce3+ monotonically increases with increase of Tb3+ concentration. The critical energy transfer distance between Ce3+ and Tb3+ was also calculated by methods of concentration quenching and spectral overlapping. Experimental analysis and theoretical calculations reveal that the dipole–dipole interaction should be the dominant mechanism for the Ce3+–Tb3+ energy transfer.