GeBi₂Te₄/PVA nanocomposites were prepared by incorporating GeBi₂Te₄ nanopowders obtained by high-energy ball milling into a poly(vinyl alcohol) (PVA) matrix using the solution-casting method. The structural and morphological properties of the materials were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dielectric properties of the composites were studied by dielectric spectroscopy in the frequency range from 120 Hz to 10⁶ Hz and at temperatures between 20 and 100 °C. The frequency and temperature dependences of the dielectric permittivity, dielectric loss function, dielectric loss tangent, and electrical conductivity were analyzed. The results revealed pronounced dielectric dispersion and relaxation behavior associated with Maxwell–Wagner–Sillars interfacial polarization at the GeBi₂Te₄/PVA interfaces. The electrical conductivity increased with increasing frequency and temperature, while the absence of percolation indicated that charge transport remained dominated by the polymer matrix. The obtained results demonstrate the potential of GeBi₂Te₄/PVA composites as functional dielectric materials.