The aim of the study was to confirm whether the coriander seeds ethanol extract (CSEE) exhibited effective antioxidant activity and oxidative stability in corn oil. The results showed that the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation radical scavenging activity were 24.4, 55.0, and 81.0, and 8.9, 16.8, and 34.3% at the concentrations of 0.25, 0.5, and 1.0 mg/mL, respectively. The ferric reducing antioxidant power (FRAP) reduction power was 284.1 μM ascorbic acid equivalent/g extract, and the total phenol content (TPC) was 31.9 μM tannic acid equivalent/g extract. Furthermore, the TPC showed positive correlations with the DPPH radical scavenging activity, ABTS cation radical scavenging, and FRAP value (p<0.01). oxygen radical absorbance by fluorescein (ORAC) analysis showed that the antioxidant activities of trolox 50 μM and CSEE 100 μg/mL were 3.1 and 4.4 times higher than those of blank AUC, respectively. In addition, CSEE reduced the amounts of conjugated diene and ρ-anisidine by 8.3 and 40.8%, respectively, in the oxidized corn oil. Thus, the coriander seeds ethanol extract is confirmed to have effective antioxidant activity and oxidative stability in corn oil, and it can be used as a natural antioxidant for preservation in food processing.