Wax extraction has been achieved from an abundant and sustainable waste residue, date palm leaves (or leaflets). Supercritical carbon dioxide extraction was utilised as a clean and efficient extraction technology in this process. Extraction conditions including pressure and temperature have been optimised using response surface methodology (via a 2x2 factorial experimental design). The highest yield obtained was 3.49% at 400 bar and 100 °C, which is significantly higher than other reported agricultural residues. The wax obtained at optimum condition (400 bar, 100 °C) exhibited a comparable melting point (78 °C) to carnauba wax, making it a suitable alternative or replacement for this overexploited commercial plant wax. The supercritical process required significantly shorter extraction times (with a 97% isolated wax yield after 120 min), as compared to soxhlet systems which typically required extraction times of up to 5 hours to obtain comparable yields. Supercritical carbon dioxide was utilised to tailor the extraction process and obtain waxes with different textural properties, chemical composition and melting profile (35-78 °C). An economic study for the date palm leaf wax extraction estimated a lowest cost of manufacture (COM) at €3.78 kg-1 wax. The low cost of the manufacturing, combined with high wax recovery, the thermal properties of the extract