街灯，又称为路灯，是道路、街道及公众广场上的发光照明系统。 通常在入夜或者天黑时分启动发亮，在黎明之后熄灭。 街灯的基本功能是照明，其附加作用可以是艺术作品、地标、路标、电话亭、留言板、信箱、集合地点、广告灯箱等。

路灯可以防止犯罪行为，协助保安、警察、闭路电视的监察、影像、录像等。

历史上的路灯有用煤气、火把、烛台、灯笼等。近年来大多以填充惰性气体的灯泡或是日光灯为主，部份地方开始采用发光二极管（LED）照明的路灯，以节省电力。

世界各地著名的路灯有澳门的三盏灯、香港都爹利街的煤气灯等。

A street light, light pole, lamppost, street lamp, light standard, or lamp standard is a raised source of light on the edge of a road or walkway. Modern lamps may also have light-sensitive photocells that activate automatically when light is or is not needed: dusk, dawn, or the onset of dark weather. This function in older lighting systems could have been performed with the aid of a solar dial. Many street light systems are being connected underground instead of wiring from one utility post to another.