This work demonstrates the luminescent properties of Ba₃Lu₂B₆O₁₅ phosphors doped with Eu³⁺ ions for the first time. The Ba₃(Lu_1–xEu_x)₂B₆O₁₅ (x = 0.01–0.375) phosphors have been prepared using a multi-step high-temperature solid-state synthesis. X-ray diffraction measurements verify the successful isomorphic substitution of the Lu³⁺ sites by the Eu³⁺ ions. The luminescence properties and its dependence on the crystal structure of Ba₃(Lu_1–xEu_x)₂B₆O₁₅ have been reported in this work. There are two nonequivalent sites in this crystal structures occupied by lutetium, both of them can be consistently substituted by the Eu³⁺ ions. The highest emission intensity with quantum yield of 17% was demonstrated by Ba₃(Lu_0.82Eu_0.18)₂B₆O₁₅ powder. Increase of Eu³⁺ doping concentration leads to gradual change of chromaticity from violet to red. It was expected that Ba₃(Lu_1–xEu_x)₂B₆O₁₅ phosphors can be used as a phosphor with predicted chromaticity under LED excitation.