An alley or alleyway is a type of road found in densely populated urban areas. Alleys usually run parallel to the rear of buildings to allow for delivery and collection. Originally required for waste collection, delivery of coal (before the widespread adoption of central heating), or rear access for fire engines and parking.

The reduced usage of alleys has resulted in their decline. Under use, poor maintenance, poor night time illumination and narrow width has contributed to an increase in anti-social or illegal activities such as:

Modern urban developments rarely incorporate alleys. Installation of gates to restrict alleyway access have significantly reduced burglary rates.

The term service road is also used in the United Kingdom. In Australia the terms lane, laneway and serviceway are used.