Southside or South Side is a neighborhood in western East Chicago, Indiana.

Together with Northside and Roxana, it makes up "East Chicago proper," as distinct from Indiana Harbor.

[1] Southside is bounded on the north by the commercial corridor along Chicago Avenue (Indiana State Road 312), and on the south by the Grand Calumet River.

[1] To the east, the residential area is bounded by Indianapolis Boulevard; beyond that lies the industrial district along the Indiana Harbor and Ship Canal.

[2] Most of the residential development in East Chicago's first decades, prior to the 20th century, took place in this neighborhood.