直接还原铁是一种在低温下将铁矿石直接还原成的金属铁制品。含碳量低、杂质少，常作为冶炼高级合金钢和纯净钢的原料。

Direct-reduced iron (DRI), also called sponge iron, is produced from direct reduction of iron ore (in the form of lumps, pellets or fines) by a reducing gas produced from natural gas or coal. The reducing gas is a mixture, the majority of which is hydrogen (H₂) and carbon monoxide (CO) which act as reducing agents. This process of reducing the iron ore in solid form by reducing gases is called direct reduction.