Abstract: Candlenut oil was extracted using supercritical CO2 (SC‐CO2) with an optimization of parameters, by the response surface methodology. The ground candlenut samples were treated in 2 different ways, that is, dried in either a heat oven (sample moisture content of 2.91%) or dried in a vacuum oven (sample moisture content of 1.98%), before extraction. An untreated sample (moisture content of 4.87%) was used as a control. The maximum percentage of oil was extracted from the heat‐oven‐dried sample (77.27%), followed by the vacuum‐oven‐dried sample (74.32%), and the untreated sample (70.12%). At an SC‐CO2 pressure of 48.26 Mpa and 60 min of extraction time, the optimal temperatures for extraction were found to be 76.4 °C, 73.9 °C, and 70.6 °C for the untreated, heat‐oven‐dried, and vacuum‐oven‐dried samples, respectively. The heat‐oven‐dried sample contains the highest percentage of linoleic acid, followed by the untreated and vacuum‐oven‐dried samples. The antiradical activity of candlenut oil corresponded to an IC50 value of 30.37 mg/mL.