Lanthanum doped MgTiO3 (La-MgTiO3; n(La):n(Mg) = 0.05:0.95) was synthesised using a sol–gel method, and a layer of this material was supported on quartz microspheres to produce La-MgTiO3(x%)/SiO2 microspheres (LMTO(x%)/SiO2; where x% represents the weight fraction of La-MgTiO3 in the microspheres). The crystal size of MgTiO3 decreased from 43.4 nm in La-MgTiO3 to 29.2 nm in LMTO(20%)/SiO2, and the bandgap energies increased from 3.34 eV (La-MgTiO3) to 3.91 eV (LMTO(20%)/SiO2). The supported La-MgTiO3 contributed the most to the total surface area of the LMTO(x%)/SiO2 microspheres; further, the specific surface area of the microspheres decreased with decreasing La-MgTiO3 content. The photoluminescence intensity of the microspheres was significantly lower than that of La-MgTiO3. The activity of La-MgTiO3 was enhanced after loading onto the quartz microspheres. The maximum photocatalytic activity was obtained using LMTO(40%)/SiO2, while the azophloxine degradation efficiency slightly decreased after five reaction cycles.