Industrial development is currently placing considerable pressure on the environment through the extensive use of natural raw materials and waste generation. Palm oil fuel ash (POFA) is an abundant waste material generated by the palm oil industry that is amorphous and has a high silica content. This work aimed to study the possibility of using thermally treated POFA (TTPOFA) in the normal triaxial porcelain composition of kaolin, feldspar, and quartz. The POFA was heat treated at 800 ℃ in an electric chamber furnace for 90 min. This thermal treatment served to eliminate any excess carbon and other unburned organic materials. The effect of the substitution of quartz with TTPOFA on the physical and mechanical properties of the final product was evaluated. The results showed that the chemical composition of POFA was significantly improved through thermal treatment, with the silica (SiO2) content increasing from 55.00% to 78.24% after treatment. A maximum compressive strength of 247 MPa and a high bulk density value of 2.44 g/cm3 were achieved in porcelain with 15 wt. % TTPOFA. X-ray diffraction analysis revealed the presence of quartz and mullite phases, which favor high mechanical strength, while the microstructure showed few small pores, which explains its low water absorption of 0.024%. The thermal treatment of POFA has proven to be an effective method for enhancing its properties, making it a promising waste material for use as a source of silica. Due to these enhanced properties, the addition of TTPOFA showed great potential as a raw material in porcelain applications, which could be regarded as an economic benefit and an important relief on waste disposal issues.