We studied here synthesis, characterization, and magnetic properties of YIG (yttrium-iron-garnet, Y3Fe5O12) and Ce-doped YIG (CexY3-xFe5O12) thin films prepared by using a sol-gel technique for magneto-optical applications. Pure YIG and Ce-doped YIG films were deposited on a glass and Si (100) substrates out of a solution prepared from Ce, Y, and Fe-based precursors, solvent, and chelating agent at low temperature using the sol-gel technique. Prior to coating process, solution characteristics that influence the intended thin film structure were determined using turbidimeter, pH meter, and rheometer machines. Film thickness was monitored with varying sol-gel solution's properties and spin coating's process parameters. Since we mainly want to improve the magnetic properties of our films, an optimum sol-gel solution containing cerium, yttrium, and iron precursors were found, and a garnet phase was formed after annealing at temperatures between 700 and 1,000 degrees C for 2 h in air. The thermal, structural, and microstructural properties of the films were characterized using DTA/TG, XRD, and SEM-EDS. The magnetic properties of the films produced by doping with Ce with an optimal process conditions were investigated through VSM device. The films include micro and nanosize CeO2 regions because of using partially dissolved Ce precursor in the solution. Our preliminary study revealed that a significant improvement in magnetic properties of polycrystalline YIG thin films have been achieved through the substitution of Ce.