Silver Spring is an urbanized, unincorporated area in Montgomery County, Maryland, USA. After Baltimore and Columbia, Silver Spring is the third most populous Census Designated Place in Maryland. The boundaries of Silver Spring are defined differently by various governmental and business entities. In its most common definition, Silver Spring would be the second most populous "city" in Maryland, after Baltimore.

The urbanized, oldest, and southernmost part of Silver Spring is a major business hub that lies at the north apex of Washington, D.C.. As of 2004, the Central Business District (CBD) held of office space, 5216 dwelling units and 17.6 acres of parkland. The population density of this CBD area of Silver Spring was 15,600 per square mile all within and approximately 2½ square miles in the CBD/downtown area. The community has recently undergone a significant renaissance, with the addition of major retail, residential, and office developments. Notably, Discovery Communications' world headquarters are located downtown.

Silver Spring takes its name from a mica-flecked spring discovered there in 1840 by Francis Preston Blair, who subsequently bought much of the surrounding land. Acorn Park, tucked away in an area of south Silver Spring away from the main downtown, is believed to be the site of the original spring.