The thermal properties of epoxy composites reinforced with iron ore tailings were used to investigate the thermal performance of the composite as heat resistant material. Thermal properties are important parameters for determining the behaviour and appropriate applications of materials. This paper focuses on investigating the thermal performance of epoxy composite reinforced with iron ore tailings (IOT) of particles sizes 150 µm, 10% reinforced. The thermal properties of the selected epoxy-IOT composite were specific heat capacity – 2352 J/kg-K, thermal resistivity – 4.788 °C-m/W, thermal diffusivity – 0.089 mm2/s and Thermal conductivity – 0.209 W/m-K. The selected epoxy-IOT composite was numerically compared with an existing material (gypsum board) of the following thermal properties: specific heat capacity – 1090 J/kg-K, thermal resistivity – 3.87°C-m/W, thermal diffusivity – 0.333 mm2/s and Thermal conductivity – 0.258 W/m-K. The numerical analysis was done using Autodesk Fusion360, by modelling the materials as slabs.The heat transfer process of the composite and the prediction of the heat resistance capability were explained by comparing the results with an existing material (gypsum plasterboard) using their mechanical and thermal properties.The numerical results indicated that the epoxy-IOT composite has lower minimum temperature and thermal stress compared with the existing material (gypsum board), which implies that epoxy-IOT composite when used as a heat insulator will resist heat and sustain thermal stress better than the gypsum board of the same geometry under the same conditions. In conclusion, an epoxy-IOT composite of appropriate mixing ratio and geometry can be comfortable use as heat resistant materials. Keywords— Epoxy-IOT, Numerical Analysis, Temperature Distribution, Thermal Performance, Thermal Stress