Genres: Card / Board / Parlor
Release Date: 1991
Publisher: Microsoft
Developer: Jim Horne
FreeCell, also known as Microsoft FreeCell, is a computer game included in Microsoft Windows, based on a card game with the same name. It is one of the most widely used Windows programs, estimated to be ahead of Word and Microsoft Excel. It has been included with every release of the Windows operating system since 1995, which has greatly contributed to the original game's popularity.

Paul Alfille implemented Freecell in 1978 for the PLATO computer system at CERL; by the early 1980s Control Data Corporation had published it for all PLATO systems. Jim Horne, who enjoyed playing Freecell on the PLATO system at the University of Alberta, published a shareware $10 DOS version with color graphics in 1988. That year Horne joined Microsoft, and later ported the game to Windows.

The Windows version was first included in Microsoft Entertainment Pack Volume 2 and later the Best Of Microsoft Entertainment Pack. It was subsequently included with Win32s as an application that enabled the testing of the 32-bit thunking layer to ensure that it was installed properly. However, FreeCell remained relatively obscure until it was released as part of Windows 95. In Windows XP, FreeCell was extended to support a total of 1 million card deals.