High-oleic low-linolenic acid soybean oil (HOLLSB, Plenish((R))) is an emerging new oil with projections of rapid expansion in the USA. HOLLSB has important technological advantages, which are expected to drive a gradual replacement of commodity oils used in food applications such as soybean oil. A key technological advantage of HOLLSB is its relatively high oxidation stability. This oxidation stability is the result of a favorable fatty acid composition, high (76%) oleic acid, low linoleic (6.7%), and alpha-linolenic (1.6%) acids, and high concentration of tocopherols (936 ppm) after refining, enriched with the gamma-homolog (586 ppm). A detailed analysis of the fatty acid composition of this HOLLSB by gas chromatography-mass spectrometry allowed the identification and structural determination of 9-cis-heptadecenoic acid (or 17:1n-8). To our knowledge, this is the first time 9-cis-heptadecenoic acid has been unequivocally reported in soybean oil. This unusual fatty acid component has the potential to be used as a single authenticity marker for the quantitative assessment of soybean oil. The Rancimat induction period (IP) of Plenish((R)) (16.1 hours) was higher than those of other commercially available high-oleic oils, such as canola (13.4 hours), and Vistive((R)) Gold (10 hours), a different variety of soybean oil. Plenish((R)) showed the same IP as high-oleic sunflower oil. Plenish((R)) shows a modest increase in oxidation stability with the external addition or relatively high concentrations of tocopherols. The characteristic high oxidative stability of Plenish((R)) may be further enhanced with the use of nontocopherol antioxidants.