The Obotrites (), also commonly known as the Obodrites, Abotrites, or Abodrites, were a confederation of medieval West Slavic tribes within the territory of modern Mecklenburg and Holstein in northern Germany (see Polabian Slavs). For decades they were allies of Charlemagne in his wars against Germanic Saxons and Slavic Veleti. In 798 the Obodrites, ruled by prince Drożko, defeated Saxons in the battle under Święciana. The still heathen Saxons were dispersed by the emperor, and part of their former land in Holstein, including Hamburg, was awarded to the Obotrites in 804, as a reward for their victory.

The Bavarian Geographer, an anonymous medieval document compiled in Regensburg in 830, contains a list of the tribes in Central Eastern Europe to the east of the Elbe. The list includes the Nortabtrezi (Obotrites) - with 53 civitates.
Adam of Bremen referred to them as the Reregi because of their lucrative trade emporium Reric. In common with other Slavic groups, they were often described by Germanic sources as Wends.
thumb|right|225px|Map of the Billunger Mark (ca. 1000 AD) showing different tribes of the Obotritic confederation
The main tribes of the Obotritic confederation were:

• the Obotrites proper (Wismar Bay to Lake Schwerin);

• the Wagrians (eastern Holstein);

• the Warnower (the upper Warnow and Mildenitz);

• the Polabians proper (between the Trave and the Elbe).

Other tribes associated with the confederation include:

• the Linonen near Lenzen,

• the Travnjane near the Trave,

• the Drevani in the Hanoverian Wendland and the northern Altmark.

As allies of the Carolingian kings and the empire of their Ottonian successors, the Obotrites fought from 808 to 1200 against the kings of Denmark, who wished to rule the Baltic region independently of the empire. When opportunities arose, for instance upon the death of an emperor, they would seek to seize power; and in 983 Hamburg was destroyed by the Obotrites under their king, Mstivoj. At times they levied tribute from the Danes and Saxons. Under the leadership of Niklot, they resisted a Christian assault during the Wendish Crusade.

German missionaries such as St Vicelinus converted the Obotrites to Christianity. In 1170 they acknowledged the suzerainty of the Holy Roman Empire, leading to Germanisation and assimilation over the following centuries. However up to the late 15th century most villagers in the Obotritic area were still speaking Slavic dialects (Polabian language), although subsequently their language changed to German. The Polabian language survived until the beginning of the 19th century in what is now the German state of Lower Saxony.

Some of the Obotrites also migrated to the south and settled in the Pannonian Plain, where the Bodrogiensis county of the medieval Kingdom of Hungary was named after them.