Mitchigamea or Michigamea or Michigamie were a tribe in the Illinois Confederation. Not much is known about them and their origin is uncertain. Originally they were said to be from Lake Michigan, perhaps the Chicago area. Mitchie Precinct, Monroe County in Southwestern Illinois takes its name from their transient presence nearby, north of the French Fort de Chartres in the American Bottom along the Mississippi. One of their villages in the American Bottom, inhabited from 1730 until 1752, is one of the region's premier archaeological sites; it is known as the "Kolmer Site".
It is suggested that the people later moved to Arkansas under pressure from the Iroquois. Their most well known leader was Chief Chicagou. In 1673, Marquette and Joliet needed a translator from Miami-Illinois to understand the Michigamea; most contact was in Plains Sign Language. Jean-Bénard Bossu provides two sentences from the mid-18th century which according to John Koontz indicate that Michigamea was a Siouan language of the Mississippi branch.