The Illinois Confederation, sometimes referred to as the Illiniwek or Illini, is a group of twelve to thirteen Native American tribes in the upper Mississippi River valley of North America.

The tribes are the Kaskaskia, the Cahokia, the Peoria, the Tamaroa, Moingwena, Michigamea, Albiui, Amonokoa, Chepoussa, Chinkoa, Coiracoentanon, Espeminkia, Maroa, Matchinkoa, Michibousa, Negawichi, and Tapouara.

At the time of European contact in the 17th century, they were believed to number several thousand people.