Open Market was an ecommerce software startup, founded in  Cambridge, Massachusetts in early 1994. It went public in 1996 on the Nasdaq exchange under the symbol OMKT, as one of the first ecommerce IPOs. It relocated to Burlington, Massachusetts in early 1998.

This article is about an economic concept. For a physical location, see Market (place).

The term open market is used generally to refer to a situation close to free trade and in a more specific technical sense to interbank trade in securities.