Selenium (Se) is an essential micronutrient for humans and other animals, and it plays an important role in antioxidant function, thyroid hormone metabolism, male fertility, and immune responses. Human Se is mainly acquired from plant foods in the diet. However, the average daily Se intake is insufficient in China to meet the requirements of human health because of the low Se concentrations in plant foods. Sunflower (Helianthus annuus L.) is an important oil crop for seed oil production. Sunflower oil contains the highest concentration of linoleic acid among the vegetable oils. People in many countries around the world love the seeds, and fried sunflower seeds are a favorite snack in China. Thus, increasing the Se concentration of sunflower seeds may be of great significance for improving Se intake. Production of Se-enriched sunflower is an efficient, inexpensive, and simple strategy to provide supplemental Se for the human diet.