Jäger (singular [der] Jäger, plural [die] Jäger, German pronunciation: [ˈjɛːɡɐ]; "hunter") is a German military term referring to specific light infantry units.

In German-speaking states during the early modern era, the term Jäger came to denote light infantrymen whose civilian occupations (mostly hunters and foresters) made them well-suited to patrolling and skirmishing, on an individual and independent basis, rather than as part of a large-scale military unit or traditional line infantry. As a consequence, Jäger was used to describe skirmishers, scouts, sharpshooters and runners.

The word's usage and derivatives broadened over time. For instance, Feldjäger was the name given by the Prussian Army to scouts and runners. Conversely, in the modern German army (Bundeswehr), Feldjäger is the name given to military police.

Jäger is usually translated into English as:

• "rifleman" (in an infantry role) or "Rifles" (in regimental names); and
• "ranger" (especially in North American English; see below).

In English Jäger is often written as jaeger (both pl. and sgl.) or anglicised as jager (pl. jagers) to avoid the umlaut.