PMMA/PEG and PMMA/PEG doped with SiO2, TiO2, and Al2O3 were fabricated using the solution-casting technique. The composites were characterized by X-ray diffraction and scanning electron microscopy (FE-SEM), which revealed that the amorphous nature of PMMA/PEG blend doped with Al2O3 was hindered by the crystalline nature of those doped with SiO2 and TiO2. The absorption of PMMA/PEG blend doped with Al2O3 is higher, band gap energies were decreased from 4.90 eV for PMMA/PEG blend to 4.03 eV, 3.09 eV, and 2.09 eV for SiO2, TiO2, and Al2O3 doped PMMA/PEG blend, respectively. The dielectric constant, ε′ has a high value (2 × 104) for samples PMMA/PEG and SiO2/PMMA/PEG. While dielectric loss ε″\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\varepsilon ^{{\\prime \\prime }} } \\right)$$\\end{document}-values decreased to < 100 for TiO2/PMMA/PEG and Al2O3/PMMA/PEG. Further, the fabricated composite SiO2/PMMA/PEG led to improvement the optical and dielectric properties compared with PMMA/PEG for optoelectronic such as manufacturing of optical fiber cables application. The results show TiO2/PMMA/PEG and Al2O3/PMMA/PEG are multifunctional can be used as low-permittivity nanodielectric and substrates to design the next generation of flexible electronic devices.