The addition of graphene as an efficient nano-filler to different polymer matrices lead to a substantial improvement in different physical properties which, as a result, pave the way towards promising applications. In this work, Polystyrene (PS) was reinforced with different low loadings of graphene oxide (GO). The latter was prepared according to the Hummers method. The incorporated weight fractions were (0.01, 0.05, 0.1, 0.25, 1.0) wt. %. Solution blending was the adopted approach to prepare the nanocomposites. The resulted nanocomposites were characterised compared to the neat polymer. Many tools were employed to investigate the structure, morphology, thermal, and thermo-mechanical behaviour of GO, neat polymer, and the nanocomposites. The structural and morphological outcome for GO and PS was confirmed compared to the literature. The outcome confirmed as well the good dispersion of GO nano-sheets in the PS. The thermal and thermo-mechanical properties were enhanced for the nanocomposites compared to the neat polymer. The results emphasised the improvement of nanocomposites' performance as the inclusion of GO went higher.