Valerian (Valeriana officinalis, Caprifoliaceae) is a perennial flowering plant, with heads of sweetly scented pink or white flowers that bloom in the summer and can reach a height of 1.5 metres (5 ft). Valerian flower extracts were used as a perfume in the 16th century.

Native to Europe and parts of Asia, valerian has been introduced into North America. The flowers are frequently visited by many fly species, especially hoverflies of the genus Eristalis. It is consumed as food by the larvae of some Lepidoptera (butterfly and moth) species including the grey pug.

Other names used for this plant include garden valerian (to distinguish it from other Valeriana species), garden heliotrope (although not related to Heliotropium), setwall and all-heal (which is also used for plants in the genus Stachys). Red valerian, often grown in gardens, is also sometimes referred to as "valerian", but is a different species (Centranthus ruber) from the same family and not very closely related.

Crude extract of valerian root is sold as a dietary supplement in the form of capsules. Valerian root may have sedative and anxiolytic effects.

The amino acid valine is named after this plant.