榛子（Hazelnut），亦作榛果，是榛属植物的的坚果，果皮坚硬，果仁可食。我们日常食用的榛子，其实是取自欧榛果实的果仁。这种欧榛仁，是国际贸易市场四大坚果之一。榛果与中国北方野生的平榛果实虽然同属榛属，但平榛的果实较小，口味不太一样。目前自中国出口的榛果，其实是欧榛跟中国平榛进行杂交的新品种。

榛子在土耳其、意大利、希腊、格鲁吉亚、西班牙加泰罗尼亚南部、英国肯特郡和美国俄勒冈州、华盛顿州进行商业化生产。土耳其是世界上最大的榛子产地，其产量占世界的75%。

榛子含有丰富的蛋白质和不饱和脂肪，并含有硫胺和维他命B。

Hazelnut is the nut of the hazel and therefore includes any of the nuts deriving from species of the genus Corylus, especially the nuts of the species Corylus avellana. It is also known as cobnut or filbert nut according to species. A cob is roughly spherical to oval, about 15–25 millimetres (0.59–0.98 in) long and 10–15 millimetres (0.39–0.59 in) in diameter, with an outer fibrous husk surrounding a smooth shell. A filbert is more elongated, being about twice as long as its diameter. The nut falls out of the husk when ripe, about seven to eight months after pollination. The kernel of the seed is edible and used raw or roasted, or ground into a paste. Hazelnuts are also used for livestock feed, as are chestnuts and acorns. The seed has a thin, dark brown skin, which is sometimes removed before cooking.