The Singel is a canal in Amsterdam which encircled the city in the Middle Ages. It served as a moat around the city until 1585, when Amsterdam expanded beyond the Singel. The canal runs from the IJ bay, near Central Station, to the Muntplein square, where it meets the Amstel river. It is now the inner-most canal in Amsterdam's semicircular ring of canals.

The canal should not be confused with the Singelgracht canal, which became the outer limit of the city during the Dutch Golden Age in the 17th Century.

Other Dutch towns also have ring-shaped canals named Singel.

Amsterdam's famous flower market, Bloemenmarkt, is located along the Singel between Koningsplein and Muntplein squares. The market stalls are actually boats floating in the canal.

Part of the Singel has been designated a red-light district, with prostitutes offering their services from behind red-lit windows. The area, known as the Singelgebied, is located near Lijnbaanssteeg and Oude Nieuwstraat. Yab Yum, one of Amsterdam's most exclusive brothels until closed by the local authority in January 2008, was located at Singel 295.

The Singel is lined by many beautiful, richly decorated canal houses built during the Dutch Golden Age. Notable buildings along the canal include: