Fescue (Festuca) is a genus of about 300 species of perennial tufted grasses, belonging to the grass family Poaceae (subfamily Pooideae). The genus has a cosmopolitan distribution, although the majority of the species are found in cool temperate areas. The genus is closely related to ryegrass (Lolium), and recent evidence from phylogenetic studies using DNA sequencing of plant mitochondrial DNA shows that the genus lacks monophyly. As a result plant taxonomists have moved several species, including the forage grasses tall fescue and meadow fescue, from the genus Festuca into the genus Lolium.

Fescues range from small grasses only 10 cm tall or less with very fine thread-like leaves less than 1 mm wide, to tall grasses up to 2 m tall with large leaves up to 60 cm (2 ft) long and 2 cm (3/4 in.) broad.

Fescue pollen is a significant contributor to hay fever.

The fescues contain some species which are important grasses for both lawns (particularly the fine-leaved species, highly valued for bowling greens) and as pasture and hay for livestock, being a highly nutritious stock feed. Fescues are also quite common on golf courses of the coastal U.S. and the U.K., usually beyond the second cut in the rough. Fescue is easily established on bare ground, out-competing other plants and persisting over several years, and so is often used in soil erosion control programs, most notably tall fescue, one cultivar of which, Kentucky 31 (Festuca arundinacea), was used in land reclamation during the dust bowl period in the 1930s in the US.