Adobe Flash Player (known in Internet Explorer, Firefox, and Google Chrome as Shockwave Flash) is a discontinued computer program for viewing multimedia content, executing rich Internet applications, and streaming audio and video content created on the Adobe Flash platform. It can run from a web browser as a browser plug-in or independently on supported devices. Originally created by FutureWave under the name FutureSplash Player, it was renamed to Macromedia Flash Player after Macromedia acquired FutureWave in 1996. After Adobe acquired Macromedia in 2005, it was developed and distributed by Adobe as Adobe Flash Player. It is currently developed and distributed by Zhongcheng for users in China, and by Harman International for enterprise users outside of China, in collaboration with Adobe.

Flash Player runs SWF files that can be created using Adobe Flash Professional, Adobe Flash Builder, or third-party tools such as FlashDevelop. Flash Player supports video and raster graphics; vector graphics; 3D graphics; embedded audio; and an object-oriented scripting language called ActionScript, which is based on ECMAScript (similar to JavaScript). Internet Explorer 11 and Microsoft Edge Legacy since Windows 8, along with Google Chrome on all versions of Windows, came bundled with a sandboxed Adobe Flash Player plug-in.

Flash Player once had a large user base, and was required to run many web games, animations, and graphical user interface (GUI) elements embedded in web pages. Adobe stated in 2013 that more than 400 million, out of over 1 billion connected desktops, updated to new versions of Flash Player within six weeks of release. However, Flash Player became increasingly criticized for poor performance, consumption of battery on mobile devices, the number of security vulnerabilities that had been discovered in the software, and its nature as a closed platform controlled by Adobe. Apple co-founder Steve Jobs was highly critical of Flash Player, having published an open letter criticising the platform and detailing Apple's reasoning for not supporting Flash on its iOS device family. Its usage further waned due to more modern web standards which replaced some of Flash's functionality, reducing the need for third-party plugins.

This led to the eventual deprecation of the platform. Flash Player was officially discontinued on 31 December 2020, and its download page was removed two days later. Since 12 January 2021, Flash Player (original global variants) versions newer than 32.0.0.371, released in May 2020, refuse to play Flash content and instead display a static warning message. The software remains supported in mainland China and in some enterprise variants.