Biodegradable glycerol-derived alkyd resins were synthesized from glycerol and maleic anhydride by polycondensation reactions. One set of glycerol-derived alkyd resin/clay nanocomposites was successfully prepared by melt blending maleic anhydride-glycerol precursors with organoclays. These clays had been pretreated with methyl tallow bis-2-hydroxylethyl ammonium chloride salt (yielding a nanocomposite designated clay30B), and some samples of the clay30B were further treated with the diglycidyl ether of bisphenol A (DGEBA) (clay30BT). Resin/mica and resin/talc nanocomposites were also prepared, in the same way, to yield materials for purposes of comparison. The morphologies, thermostabilities, and mechanical properties of the resulting nanocomposites were investigated in detail. X-ray scattering results and transmission electron microscopy (TEM) images clearly indicated that 30BT was further delaminated by the DGEBA, and that the clay30B and clay30BT were mostly exfoliated and finely distributed in the alkyd resin matrix. These layered silicate fillers gave remarkable improvements in thermostability and mechanical properties even at very low loadings. Minimizing aggregation was more of a problem in the case of the mica and the talc, at least in this matrix.