A nutrient-balanced diet includes consuming various fruits, vegetables, and grains in a reasonable proportion. Oat is one of the whole grains preserved with a nutritional profile, playing a crucial role in the human diet. It is a nutrient-dense grain containing about 51-67.7% starch, 9- 20% protein, 10.1-39% dietary fiber, 2-18% lipid, 10.8% water, vitamins, and minerals. The health benefits associated with oats are partly attributed to the presence of distinctive bioactive compounds and nutrients. The bioactive compounds found in oats include beta-glucan, phenolic acids, flavonoids, tocols, phytosterols, and avenanthramides. High consumption of oats has been associated with reduced risk of cardiovascular diseases, obesity, type 2 diabetes, and some cancers, along with weight control, glycemic index control, and improved gastrointestinal health. This paper aims to systematically review the current literature on the bioactive compounds of oats, nutrients, and their health benefits, and give a comprehensive insight into the unique properties and potential benefits of oats as a healthy grain food.