Tree nut oils are primarily composed of triacylglycerols, but also contain diacylglycerols (DAG), monoacylglycerols (MAG), free fatty acids (FFA), and other minor components, including natural antioxidants and fat‐soluble vitamins. The chemical composition of edible fats and oils largely determines their stability, quality, nutritional value, sensory properties, and potential health effects. Generally, the monounsaturated fatty acids (MUFA), predominantly oleic acid, are the major fatty acids present in tree nuts oil, followed by polyunsaturated fatty acids (PUFA) and small amounts of saturated lipids. Besides, tree nut oils contain abundant bioactive components including phytosterols, carotenoids, tocols, phospholipids, and sphingolipids. And as the major antioxidants in tree nut oil, the content of carotenoids and tocols remarkably affects the oil oxidative stability, as well as their degree of unsaturation and pigment content. Tree nuts have long been considered to be an important component of the Mediterranean diet. Their by‐products, especially defatted meals, skins, and hulls, may also be considered as excellent sources of protein and phytochemicals. Epidemiological evidence indicates that consumption of whole tree nuts may exert antioxidative stress, anti‐inflammatory, anti‐obesity, anti‐diabetes, and cardioprotective effects in animal or human body. Recent investigations have also shown that dietary consumption of either whole tree nuts, oils or polyphenol extract has beneficial effects on animal or human body, which implies that both the lipid components in oil and phenolics in defatted meal are responsible for the health‐enhanced results of tree nuts fed. In this article, the specific chemical composition, oxidative stability, and potential health effects of nine commercial tree nut oils (almond oil, hazelnut oil, pecan oil, walnut oil, pistachio oil, Brazil nut oil, pine nut oil, cashew nut oil, and macadamia nut oil) are summarized. In addition, the major amino acids profile, phenolic constituent, and health effects of tree nut by‐products are also presented.