A herbal is a book containing the names and descriptions of plants, usually with information on their medicinal, tonic, culinary, toxic, hallucinatory, aromatic, or magical powers, and the legends associated with them. A herbal may also classify the plants it describes, may give recipes for herbal extracts, tinctures, or potions, and sometimes include mineral and animal medicaments in addition to those obtained from plants. Herbals were often illustrated to assist plant identification.

Herbals were among the first literature produced in Ancient Egypt, China, India, and Europe as the medical wisdom of the day accumulated by herbalists, apothecaries and physicians. Herbals were also among the first books to be printed in both China and Europe. In Western Europe herbals flourished for two centuries following the introduction of moveable type (c. 1470–1670).

In the late 17th century, the rise of modern chemistry, toxicology and pharmacology reduced the medicinal value of the classical herbal. As reference manuals for botanical study and plant identification herbals were supplanted by Floras – systematic accounts of the plants found growing in a particular region, with scientifically accurate botanical descriptions, classification, and illustrations. Herbals have seen a modest revival in the Western world since the last decades of the 20th century, as herbalism and related disciplines (such as homeopathy and aromatherapy) became popular forms of alternative medicine.