Windows Millennium Edition, or Windows Me (marketed with the pronunciation of the pronoun "me"), is an operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It is the successor to Windows 98, and was released to manufacturing on June 19, 2000, and then to retail on September 14, 2000. It was Microsoft's main operating system for home users until the introduction of its successor Windows XP in October 2001.

Windows Me was targeted specifically at home PC users, and included Internet Explorer 5.5 (later default was Internet Explorer 6), Windows Media Player 7 (later default was Windows Media Player 9 Series) and the new Windows Movie Maker software, which provided basic video editing and was designed to be easy to use for consumers. Microsoft also incorporated features first introduced in Windows 2000, which had been released as a business-oriented operating system seven months earlier, into the graphical user interface, shell and Windows Explorer. Although Windows Me was still ultimately based around MS-DOS like its predecessors, access to real-mode DOS was restricted to decrease system boot time.

Windows Me was initially positively received when it was released, but it soon garnered a negative reception from many users due to stability problems. Windows Me is now infamously known by many as the worst version of Windows Microsoft has ever produced, being unfavorably compared with its immediate predecessor, Windows 98, several years before. In October 2001, Windows XP was released to the public, having already been under development at the time of Windows Me's release, and popularized most of Windows Me's features, while being far more stable because of it being based on the Windows NT kernel. After the release of Windows XP in 2001, mainstream support for Windows Me ended on December 31, 2003, followed by extended support on July 11, 2006.