焦油是一种黑色的粘稠液体，是有机物经过加热干馏的产物，常见的为用煤炼焦产生的煤焦油，但木材干馏也会产生木焦油，此外泥炭干馏，石油分馏产生的重油也被称为焦油。焦油可做为防腐剂。

煤焦油含有高浓度的苯，因此有毒，是多种化工产品的原料。

木焦油有清香的味道，在欧洲古代用于涂布船只、屋顶以防水，此外还用作糖果、酒和其他食品的添加剂，增加香味。烟草燃烧时会产生焦油。

焦油还可以作为治疗某些皮肤病的药品。在古代芬兰也用作药品，芬兰有一句谚语：“如果桑拿浴、酒和焦油都不起作用，这种病就没法治了。”

古代埃及制作木乃伊曾有涂布焦油的。

Tar is a black mixture of hydrocarbons and free carbon obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. Production and trade in pine-derived tar was a major contributor in the economies of Northern Europe and Colonial America. Its main use was in preserving wooden vessels against rot. The largest user was the Royal Navy. Demand for tar declined with the advent of iron and steel ships.