The Gage Group Buildings consist of three buildings located at 18, 24 and 30 S. Michigan Avenue, between Madison Street and Monroe Street, in Chicago, Illinois. They were built from 1890–1899, designed by Holabird & Roche for the three millinery firms - Gage, Keith and Ascher. The building at 18 S. Michigan Avenue has an ornamental façade designed by Louis Sullivan. It was listed on the National Register of Historic Places on November 14, 1985, and was designated a Chicago Landmark on September 11, 1996. In addition, it is a historic district contributing property for the Chicago Landmark Historic Michigan Boulevard District.