As the effects of climate change continue to alter crop-growing conditions year-to-year on both prime and marginal agricultural landscapes, we must consider the effects not only on yield but also on quality. This is particularly true for oilseed crops. In this review, we explore the importance of oilseeds in general and the specific uses of major oilseed crops including soybean, sunflower, canola, peanut, and cottonseed. We review the physiology of seed oil production, from the perspective of the plant's adaptation to environmental changes. Of particular importance is the role of temperature and water availability on oil synthesis. We then discuss how this influences genetic variation, phenotype variability due to environment, and the interaction of genetics and environment to affect composition and yield of vegetable oils. The ability to predict these effects using genomics and bioinformatics is an important new frontier for breeders to maximize stability of a desired fatty acid composition for their crop over increasingly extreme agricultural environments.