In this work, we have synthesized the ZnO nanoflakes using three different solvents, i.e., isopropyl alcohol (IPA), DI (de-ionized) water and ethanol via co-precipitation technique. XRD analysis revealed the hexagonal wurtzite crystal structure for all synthesized samples. The crystallite size is least for ZnO nanoflakes synthesized using ethanol and highest for IPA by applying Scherrer's formula as well as W–H plot. The optical properties were analyzed using UV–Visible spectroscopy and revealed that the maximum optical band gap has been obtained using ethanol as a solvent while the least band gap is observed for IPA. The expansion of light absorption region from UV to visible region can lead to its application in various fields such as optical LEDs, photocatalysis, laser diodes, etc. FTIR spectrum verifies the presence of vibrational modes of the ZnO bond, stretching and bending bonds of OH bonds and O=C=O stretching bond in the prepared samples. The plot for frequency-dependent dielectric loss exhibits the change in dielectric properties. The Nyquist diagrams reveal the semi-circular arc depicting the variation between real and imaginary parts of impedance. The results show that the electrical conductivity increases with frequency and temperature. The activation energy is found using Arrhenius equation with the plot of conductivity versus temperature and the values of activation energy for ZnO nanoflakes synthesized using IPA, DI water, and ethanol is found to be 0.23 eV, 0.29 eV and 0.41 eV, respectively.