Novel single-phase full-color-emitting Ba9Lu2Si6O24: Ce3+/Mn2+/Tb3+ phosphors were successfully synthesized by a high-temperature solid-state reaction method. Analysis of the X-ray diffractograms of the produced phosphors suggests that all the luminescence doping cations preferably occupy the Ba2+ sites in the host lattice. Li+ were used according to Ce3+ and Tb3+ concentration as a charge compensation regent. Under UV excitation, the single Ce3+-doped phosphor exhibits an intense blue emission band that peaks at 424 nm. In the codoped phosphors, the experimental results suggest that an efficient energy transfer mechanism from Ce3+ to Tb3+ and Mn2+ results in the generation of a green emission in the Tb3+-doped phosphors and a red emission in the Mn2+ doped ones. The triple-doped phosphors, which contained specific concentrations of Ce3+, Mn2+, and Tb3+ ions, generated a tunable (in a wide range) white light which had good color rendering index values. Thermal behavior of the present phosphors was investigated which shows better characteristics. This result qualifies the produced powders as potential single-phase trichromatic white light-emitting phosphors.