Thermal properties of materials such as plastic matrix composite is one of the important parameters for determining their behaviour and relevant applications. This present work focuses on determining the thermal behaviour of epoxy and polypropylene (PP) matrix composite reinforced with iron ore tailings (IOT) particulates of sizes 150 µm, 212 µm and 300 µm at various loadings of 5%, 10%, 15%, 20%, 25%, and 30%. The thermal behaviour of the developed composites was investigated experimentally using a KD2 pro thermal analyser. The results obtained from the experiment showed that increasing filler loading in epoxy leads to increased specific heat capacity and thermal resistivity. The maximum values recorded for the thermal resistivity and specific heat capacity were 0. 592°C.m/W and 2.352 J/kgK respectively. Thermal conductivity and thermal diffusivity of values 0.168W/mK and 0.089 mm²/s respectively were the lowest obtained for the epoxy matrix composite. It was also observed that addition of IOT in PP had significant effect on the thermal properties of the PP composite. Thermal conductivity and thermal diffusivity were found to increase with increased particle loading compared to the pure PP sample; the highest value being 2.235 W/mK and 5.51 mm²/s for thermal conductivity and thermal diffusivity respectively while low values of 0.05 Cm/W and 0.371 J/kgK was recorded for thermal resistivity and specific heat capacity. The presence of iron ore tailings reduces the thermal conductivity and diffusivity in epoxy but increases the conductivity and diffusivity in polypropylene. Keywords— Composite, Epoxy, IOT, Polypropylene, Composite, Thermal Conductivity