In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also look different from the parts of the flower, such as the petals or sepals.

A plant having bracts is referred to as bracteate or bracteolate, while one that lacks them is referred to as ebracteate or ebracteolate.

Some bracts are brightly coloured which aid in the attraction of pollinators, either together with the perianth or instead of it. Examples of this type of bract include those of Euphorbia pulcherrima (poinsettia) and Bougainvillea: both of these have large colourful bracts surrounding much smaller, less colourful flowers.

In grasses, each floret (flower) is enclosed in a pair of papery bracts, called the lemma (lower bract) and palea (upper bract), while each spikelet (group of florets) has a further pair of bracts at its base called glumes. These bracts form the chaff that is usually removed from cereal grain during threshing and winnowing.

Bats may detect acoustic signals from dish-shaped bracts such as those of Marcgravia evenia.

A prophyll is a leaf-like structure, such as a bracteole, subtending (extending under) a single flower or pedicel. The term can also mean the lower bract on a peduncle.

The frequently showy pair of bracts of Euphorbia species in subgenus Lacanthis are the cyathophylls.

Bracts subtend the cone scales in the seed cones of many conifers, and in some cases, such as Pseudotsuga, extend beyond the cone scales.