Mangifera caesia is a tropical fruit tree in the cashew family Anacardiaceae, most commonly known in English and Malay as binjai; other names include white mango, jack mango, wani in Bali and parts of Borneo, bayuno or bauno in the Philippines, and lam-yai or bin-ya in Thailand. It is native to Malesia, especially Borneo, Sumatra, Java, Bali, Peninsular Malaysia, Brunei, Singapore, and nearby parts of Papuasia, and is also cultivated in southern Thailand and the Philippines. The genus name Mangifera refers to mango-bearing trees, while the specific epithet caesia means bluish-grey, likely referring to the plant's glaucous or greyish aspect in early botanical description.

Binjai is a large evergreen tree that may reach about 30 m in height, with a columnar bole, grey-brown fissured bark, irritant latex, massive branches, and a dense rounded or dome-shaped crown. The leaves are simple, leathery, and elliptic to oblong, with relatively long petioles compared with some related Mangifera species. Its small pink to purplish flowers are borne in panicles, followed by large obovate to ellipsoid drupes, often 10–15 cm long or larger, with thin green, yellowish, or brownish skin and pale yellow-white to milky white flesh. Wild fruits are often fibrous, strongly aromatic, sour-sweet, and pungent, while the wani form cultivated in Bali and Borneo can be sweet, juicy, and nearly fibreless.

The ripe fruit is eaten fresh, especially sweeter wani forms, but binjai is also valued as a souring and aromatic ingredient in Southeast Asian foodways. In Malaysia, Indonesia, Brunei, and Borneo it is used in sambal, pickles, preserved salted fruit, sauces, and accompaniments to fish or sago-based dishes; in Brunei, binjai is used in cacah dipping sauces for ambuyat. Balinese uses include creamy juices and spice bases for chilli condiments eaten with river fish. The fruit is not a major global commodity but is locally important in orchards, markets, home gardens, and agroforestry systems, especially among Malay, Balinese, Bornean, Bruneian, and several Philippine communities.

Binjai's nutritional significance is mainly as a hydrating, acidic fruit with vitamin C, soluble carbohydrates, organic acids, fibre, and phenolic antioxidants. Reported bioactive chemistry includes phenolic constituents associated with antioxidant and alpha-glucosidase inhibitory activity, volatile esters and alcohols responsible for its strong aroma, and Mangifera-type phenolics that may include mangiferin or related xanthones. A metabolomics study found that 70% ethanol extracts of M. caesia fruit had high phenolic content, antioxidant activity, and alpha-glucosidase inhibition. Notable volatile compounds in the fruit include ethyl 3-methylbutanoate and other esters. Potentially hazardous constituents are concentrated in the sap and unripe fruit latex such as urushiol: like other Anacardiaceae, binjai can cause contact dermatitis or irritation, and the immature fruit's white juice is reported as extremely irritating to skin and when ingested.