红土，指富含氧化铁的土，因富含氧化铁以致土壤发出棕色颜色，土质最好为黑土，最差为红土。 因长年下雨，导致腐植质保存不易，仅留下较重的氧化铁而形成。

红土土壤构造明显，通气、排水良好。土壤呈酸性，不适合种植作物，富含粘性及可塑性，生产力差，但可配合适当之肥培管理提高产量。目前大都种植茶叶、凤梨、甘蔗等农作物。于中国有些区域民众会用其制作咸鸭蛋。

Laterite is a soil and rock type rich in iron and aluminium, and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and long-lasting weathering of the underlying parent rock. Tropical weathering (laterization) is a prolonged process of chemical weathering which produces a wide variety in the thickness, grade, chemistry and ore mineralogy of the resulting soils. The majority of the land area containing laterites is between the tropics of Cancer and Capricorn.