The structural, optical, electronic, and magnetic properties of La2Co(1−x)Cr(x)MnO6 (0 ≤ x ≤ 1) double perovskites synthesized via the sol-gel auto-combustion method were systematically investigated. X-ray diffraction confirmed the formation of a single-phase monoclinic structure (P21/n space group) in all samples, with crystallite sizes decreasing as Cr content increased, as determined by the Debye-Scherrer formula. FESEM revealed an irregular chip-like morphology and a reduction in grain size with increasing Cr content at the Co site. The optical bandgap, calculated using the Tauc relation, exhibited a nonlinear dependence on Cr composition, suggesting a bandgap bowing effect. FTIR spectrum revealed a shift in La-O-La bending vibrations from 595 cm−1 (x = 0) to 618 cm−1 (x = 1) with increasing Cr incorporation. XPS analysis confirmed the presence of Cr3+, Mn3+, Mn4+, Co2+, and Co3+ ions, validating the oxidation states of the constituent elements. Magnetic measurements indicated a significant reduction in Curie temperature (TC), coercive field (HC), and remanence (Mr) with increasing Cr doping, attributed to mixed valence state and ionic radius mismatches among Co, Mn, and Cr. This study, emphasizing the magnetic, optical, and electronic properties of Cr-substituted La2CoMnO6, highlights its potential for advanced applications in spintronic and photovoltaic devices.