QuickTime is a discontinued extensible multimedia framework created by Apple, which supports playing, streaming, encoding, and transcoding a variety of digital media formats. The term QuickTime also refers to the QuickTime Player front-end media player application, which is built-into macOS, and was available for download on Windows until 2016.

QuickTime was created in 1991, when the concept of playing digital video directly on computers was "groundbreaking." QuickTime could embed a number of advanced media types, including panoramic images (called QuickTime VR) and Adobe Flash. Over the 1990s, QuickTime became a dominant standard for digital multimedia, as it was integrated into many websites, applications, and video games, and adopted by professional filmmakers. The QuickTime File Format became the basis for the MPEG-4 standard. During its heyday, QuickTime was notably used to create the innovative Myst and Xplora1 video games, and to exclusively distribute movie trailers for several Star Wars movies. QuickTime could support additional codecs through plug-ins, for example with Perian.

As operating systems and browsers gained support for MPEG-4 and subsequent standards like H.264, the need for a cross-platform version of QuickTime diminished, and Apple discontinued the Windows version of QuickTime in 2016. In Mac OS X Snow Leopard, QuickTime 7 was discontinued in favor of QuickTime Player X, which abandoned the aging QuickTime framework in favor of the AVFoundation framework. QuickTime Player X does not support video editing (beyond trimming clips) or plug-ins for additional codec support. macOS Catalina dropped support for all 32-bit applications, including the QTKit framework and the old QuickTime 7.