A novel cerium-substituted, barium yttrium silicate has been identified as an efficient blue-green phosphor for application in solid state lighting. Ba9Y2Si6O24:Ce3+ was prepared and structurally characterized using synchrotron X-ray powder diffraction. The photoluminescent characterization identified a major peak at 394 nm in the excitation spectrum, making this material viable for near-UV LED excitation. An efficient emission, with a quantum yield of approximate to 60% covers a broad portion (430-675 nm) of the visible spectrum, leading to the blue-green color. Concentration quenching occurs when the Ce3+ content exceeds approximate to 3 mol %, whereas high temperature photoluminescent measurements show a 25% drop from the room temperature efficiency at 500 K. The emission of this compound can be red-shifted via the solid solution Ba-9(Y1-yScy)(1.94)Ce0.06Si6O24 (y = 0.1, 0.2), allowing for tunable color properties when device integration is considered.