QuickTime Streaming Server (QTSS) is a server or service daemon that was built into Apple's Mac OS X Server until OS X Server 10.6.8. It delivers video and audio on request to users over a computer network, including the Internet. Its primary GUI configuration tool is QTSS Publisher and its web-based administration port is 1220. It also uses port UDP/7100. When used in conjunction with QuickTime Broadcaster, it is possible to deliver live real-time video and audio to multiple users over networks.

The protocol used has since been superseded with HTTP Live Streaming used in iOS and Mac OS.