The LaSalle–Wacker Building, at 221 North LaSalle Street (also known as 121 West Wacker Drive), is a 41-story skyscraper at the north end of the LaSalle Street canyon in the Loop community area of Chicago, Illinois, United States.

Clad in limestone and granite, the Holabird and Root-designed structure (Andrew Rebori was the associate architect) serves as an office building.

When built, the beacon on the top of the building could be seen from as far as 200 miles.

As with other buildings in Chicago, the structure is upwardly lit at night with moonlight, and the peak of building is typically lit in cobalt blue.

WFMT, America's first radio superstation, maintained studios in the building from 1954 until 1995.