A red-light district is a neighborhood where prostitution is a common part of everyday life. The term was first recorded in the United States around 1890, and derives from the practice of placing a red light in the window to indicate to customers the (often illegal) nature of the business. This is based on the biblical story of Rahab, a prostitute in Jericho who aided the spies of Joshua and identified her house with a scarlet rope.

Interestingly, one of the many terms used for a red-light district in Japanese is akasen (赤線), meaning "red-line district".

Famous red-light districts

Africa

• Wagh el Birket – Cairo, Egypt
• Avenue Lalla Yacout – Casablanca, Morocco
• Point Road – Durban, South Africa
• Petit Socco – Tangier, Morocco

Asia-Pacific

• Patpong – Bangkok, Thailand
• Sukhumvit Road Area (including Nana Plaza and Soi Cowboy) – Bangkok, Thailand
• Dashilan – Beijing, China
• Wanchai – Hong Kong
• Hira Mandi – Lahore, Pakistan
• Kamathipura – Mumbai, India
• Pattaya, Thailand
• Svay Pak – Phnom Penh, Cambodia
• Geylang – Singapore
• Kings Cross – Sydney, Australia
• St. Kilda – Melbourne, Australia
• Kabukicho – Tokyo, Japan
• Yoshiwara – Tokyo, Japan (in Edo period)

Europe

• De Wallen – Amsterdam, Netherlands
• Raval /Barri Xines – Barcelona, Spain
• Picin Park – Belgrade, Serbia
• Rue d'Aerschot – Brussels, Belgium
• József körút /Rákóczi tér – Budapest, Hungary (defunct)
• Bahnhofsviertel – Frankfurt, Germany
• Reeperbahn – Hamburg, Germany
• Intendente – Lisbon, Portugal
• Cais do Sodré – Lisbon, Portugal
• Kings Cross – London, England
• Piccadilly Circus – London, England (defunct)
• Soho – London, England
• Calle Luna – Madrid, Spain
• Navigli – Milan, Italy (defunct)
• Schwabing – Munich, Germany (defunct)
• Boulevard de Clichy – Paris, France
• Pigalle – Paris, France
• Millbay – Plymouth, England
• Union Street – Plymouth, England (defunct)
• Perlovka – Prague, Czech Republic
• Piazza Vittorio Emmanuele – Rome, Italy
• Praterstrasse – Vienna, Austria
• Spittelberg – Vienna, Austria (defunct)

North America

• The Block – Baltimore, Maryland
• Combat Zone – Boston, Massachusetts (defunct)
• Scollay Square – Boston, Massachusetts (razed)
• The Levee – Chicago, Illinois
• Sunset Boulevard – Hollywood, California
• Western Avenue – Hollywood, California
• Hotel Street – Honolulu, Hawaii
• La Merced – Mexico City, Mexico
• Zona Rosa – Mexico City, Mexico
• Storyville – New Orleans, Louisiana (defunct)
• Tenderloin – New York City, New York (defunct)
• Times Square – New York City, New York (defunct)
• Northern Liberties – Philadelphia, Pennsylvania (defunct)
• Marcy Street – Portsmouth, New Hampshire (1890s–1912)
• Commercial Street – Salt Lake City, Utah (defunct)
• Sepulveda Boulevard – San Fernando Valley, California
• Barbary Coast – San Francisco, California (defunct)
• Tenderloin – San Francisco, California
• Beacon Street – San Pedro, California (defunct)
• Venus Alley – Butte, Montana (defunct)
• The Reservation – Waco, Texas (defunct)
• 14th Street – Washington, District Of Columbia (defunct)
• Vermont Ave, NW – Washington, District Of Columbia