Graphene oxide (GO) is an excellent filler used in composite corrosion resistant coatings, but its effect is reduced by the fact that it easily forms aggregates. In order to improve the dispersion of GO in the silica matrix and hence, the corrosion inhibiting performance of the composite coatings, the GO was modified with 3-aminopropyl triethoxysilane (APTES) and poly(amidoamine) (PAMAM) dendrimer. The surface-modified graphene oxides APTES-GO and PAMAM-GO were then used as fillers in silica coatings prepared on zinc by dip coating, and their performances were compared with those of GO and reduced GO (rGO). The influence of sol aging on the performance of the composite coatings was also investigated. The methods that have been used for the evaluation of the corrosion resistance of the coatings were mainly electrochemical ones (electrochemical impedance spectroscopy) buttressed with morpho-structural characterizations. The results reveal that the surface modified GO sheets in silica matrices exhibit better results than in case of rGO and GO, and further improvements can be made by sol aging.