In this work, we study the structural and optical analysis of La1-xMgxFeO3 with x = 0.0, 0.1, 0.2, and 0.3 perovskite material. The (La,Mg)FeO3 material were synthesized by sol-gel method. The structural properties were characterized by X-Ray diffraction (XRD) while the optical properties were characterized by Fourier Transform Infrared spectroscopy (FTIR), Raman spectroscopy and UV-Vis spectrophotometry. The band gap energy was analyzed using the Kubelka-Munk (KM) method from UV-Vis spectrum. XRD analysis revealed the single phase of (La,Mg)FeO3 orthorhombic crystal structure with Pnma space group which is also confirmed by identical Raman spectrum. The crystallite size decreases with increasing Mg-content. The FTIR spectrum confirmed the La/Mg-O stretching, Fe-O stretching and Fe-O-Fe bending vibration modes. The vibration modes of (La,Mg)FeO3 material were analyzed by Raman spectroscopy and assigned to some specific Raman phonon modes. UV-Vis analysis shows decreasing band gap energy from 2.14 eV to 2.05 eV with increasing Mg-content.