Tetragnatha is a genus of long-jawed orb-weavers found all over the world. It was first described by Pierre André Latreille in 1804, and it contains hundreds of species. Most occur in the tropics and subtropics, and many can run over water. They are commonly called stretch spiders in reference to their elongated body form and their ability to hide on blades of grass or similar elongated substrates by stretching their front legs forward and the others behind them. The name Tetragnatha is derived from Greek, tetra- a numerical prefix referring to four and gnatha meaning "jaw". Evolution to cursorial behavior occurred long ago in a few different species, the most studied being those found on the Hawaiian islands. One of the biggest and most common species is T. extensa, which has a holarctic distribution. It can be found near lakes, river banks or swamps. Large numbers of individuals can often be found in reeds, tall grass, and around minor trees and shrubs.

Long-jawed orb weavers or long jawed spiders (Tetragnathidae) are a family of araneomorph spiders first described by Anton Menge in 1866. They have elongated bodies, legs, and chelicerae, and build small orb webs with an open hub with few, wide-set radii and spirals with no signal line or retreat. Some species are often found in long vegetation near water.