A series of novel green-emitting Ba5Si2O6Cl6:Eu2+ (BSOC:Eu2+) phosphors were synthesized via the high-temperature solid-state reaction route. The phase identification, elemental distribution, reflectance spectra, luminescence, and thermal stability of the BSOC:Eu2+ phosphor and its applicability in white light-emitting diodes (WLEDs) were investigated in detail. The broad excitation spectrum was observed from UV to blue light which generated a broadband emission peaking at 510 nm for the present phosphor with a good quantum efficiency of 44% and thereby it is promising for solid-state lighting applications. Temperature-dependent luminescence measurements of the BSOC:Eu2+ phosphor from 25 °C to 250 °C were performed to obtain the thermal stability of the present phosphor. Finally, a WLED was fabricated using the green-emitting BSOC:Eu2+ phosphor and commercially available red and blue phosphors pumped with a 400 nm blue chip. The CIE parameters such as color coordinate, color rendering index, color correlated temperature and luminous efficacy of radiation of the fabricated LED were measured. The suitable excitation spectra, efficient and broad emission band and excellent color parameters suggest that the synthesized phosphor could be a potential material for WLED application.