A step-wise synthetic method has been developed for the synthesis of multifunctional, magnetic luminescent nanocomposites with Fe₃O₄ nanospheres as the core encapsulated in silica and europium-doped sodium lutetium fluoride (NaLuF₄ :Eu³⁺) as the shell. X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), photoluminescence (PL), kinetics of luminescence decay and magnetic studies were used to characterize the structural, optical and magnetic properties of these nanospheres. SEM and TEM images define their spherical morphology with average crystallite size in the range of 90–180 nm. Ultraviolet excited photoluminescent properties of Eu³⁺ doped Fe₃O₄ @ SiO₂ @ NaLuF₄ nanospheres were investigated and impact of doping has been explored. Eu³⁺ as dopant ion induces highly efficient luminescence with average lifetime value of 6.235 ns. Fe₃O₄ magnetic core exhibits super- paramagnetic behavior at room temperature.