A narrow-band green-emitting LaMgAl11O19: Mn2+, Ce3+ phosphor was synthesized through high-temperature solid-state reaction. The phase, luminescent properties, and energy transfer mechanism from Ce3+ to Mn2+ in LaMgAl11O19 were systematically investigated. The results reveal that Ce3+ ions serve as effective sensitizers for Mn2+ in LaMgAl11O19, leading to enhanced green emission at 525 nm, upon 320 nm excitation. The energy transfer from Ce3+ to Mn2+ is found to occur via dipole-dipole interactions, with a calculated critical transfer distance of 14.24 & Aring;. The quantum efficiency of the optimized sample reaches 74.3 %, and the phosphor exhibits excellent thermal stability, retaining 92 % of its luminescence intensity at 150 degrees C. These results indicate the LaMgAl11O19: Mn2+, Ce(3+)phosphors exhibit high potential for wide color gamut white light-emitting diode (wLED) backlighting applications.