The houses in the Sycamore Historic District, in Sycamore, Illinois, United States, cross a variety of architectural styles and span from the 1830s to the early 20th century. There are 187 contributing properties within the historic district, 75% of the districts buildings. Many of the homes are associated with early Sycamore residents, usually prominent business leaders or politicians. Houses within the district are known by, either their street address or by a name associated with a prominent owner or builder. For most of the houses, the latter is true.

Sycamore is a city in DeKalb County, Illinois, United States. It has a commercial district based and centered on Illinois Route 64. The population was 18,577 at the 2020 census, up from 17,419 at the 2010 census. Sycamore is the county seat of DeKalb County and was named after the sycamore tree.