Lynkestis, Lyncestis, Lyngistis, Lynkos or Lyncus (Ancient Greek: Λυγκηστίς or Λύγκος Latin: Lyncestis or Lyncus) was a region and principality traditionally located in Upper Macedonia. It was the northernmost mountainous region of Upper Macedonia, located east of the Prespa Lakes.

In its earlier history, Lynkestis was an independent polity ruled by a local dynasty which claimed descent from the Bacchiadae, a Greek aristocratic family from ancient Corinth. They were ruled by a basileus, as did the rest of the tribes in Lower and Upper Macedonia. The few existing primary sources show that before the rise of Macedon it maintained connections with the Illyrians and was frequently in hostilities with the Argeads.

The inhabitants of Lynkestis were known as Lyncestae or Lynkestai (Greek: Λυγκῆσται). Hecataeus (6th century BC) included them among the Molossians, while Thucydides (5th century BC) considered them Macedonians. Most later ancient authors considered them Macedonians, while others included them among the Illyrians. Modern scholars regard them as either Macedonians, Epirotes (Molossians) or Illyrians. Some generally consider them to be Greeks of Upper Macedonia.

In the second half of the 5th century BC Lynkestis was the strongest tribal state in Upper Macedonia under king Arrhabaeus, son of Bomerus. During the Peloponnesian War the combined army of Lyncestians under king Arrhabaeus and Illyrians won against the joined forces of the Macedonian king Perdiccas II and the Spartan leader Brasidas at the Battle of Lyncestis in 423 BC.

Lynkestis was annexed or retained by the Illyrian king Bardylis after his victory against Perdiccas III of Macedon in 360 BC. At the Battle of Erigon Valley in 358 BC, the Illyrians under Bardylis were defeated by Phillip II and Lynkestis became part of Macedon. After his conquest, Philip founded Heraclea Lyncestis, which would become the main city of the area in antiquity. Although they became part of Macedon, Lynkestians retained their own basileus.

According to Hammond, the locals were recruited by Philip II to serve in the king’s army due to their common language as well as because they were accorded equal terms with the population of Lower Macedonia. Later they contributed to the Indian campaign led by Alexander the Great.

The etymology of the geographical name Lynkos/Lynkestis and tribal name Lynkestai is uncertain. The geographical names that contain the root Λυγκ- Lynk- either may refer to the "lynx" or not, and they may well be of Pre-Greek origin. It seems possible that the Greek word for "lynx" (λύγξ, λύγκος) came from those toponyms. The tribal name Lynkestes bears the typical Illyrian suffix -st-.

Lynkestis was the northernmost mountainous region of Upper Macedonia, located east of the Prespa Lakes. Lynkestis bordered with Pelagonia to the northeast, Emathia and Almopia to the southeast, and Orestia, Eordaia and the Haliacmon river at some distance to the south. To the west Lynkestis bordered with Illyria. Lynkestis was strategically very important because the major east–west route and one of the north–south routes passed through the core of this region.