The Metro East is an urban area in Southern Illinois, United States that contains the eastern and northern suburbs and exurbs of St. Louis, Missouri. It encompasses five counties in the Greater St. Louis area and constitutes the second-most populous urban area in Illinois. The region's most populated city is Belleville, with 42,404 residents.

Southern Illinois is a region of the U.S. state of Illinois comprising the southern third of the state, principally south of Interstate 70. Part of downstate Illinois, it is bordered by the two most voluminous rivers in the United States: the Mississippi below its connection with the Missouri River to the west and the Ohio River to the east and south, with the Wabash as a tributary. Some areas of Southern Illinois are known historically as Little Egypt.