Microsoft Entertainment Pack, also known as Windows Entertainment Pack or simply WEP, is a collection of 16-bit casual computer games for Windows. There were four Entertainment Packs released between 1990 and 1992. These games were somewhat unusual for the time, in that they would not run under MS-DOS. In 1994, a compilation of selected games from the previous four Entertainment Packs was released called The Best of Microsoft Entertainment Pack. A Game Boy Color version was released in 2001.

Microsoft advertised Entertainment Packs for casual gaming on office computers. The boxes had slogans like "No more boring coffee breaks" and "Only a few minutes between meetings? Get in a quick game of Klotski". The marketing succeeded; Computer Gaming World in 1992 described the series as "the Gorillas of the Gaming Lite Jungle", with more than 500,000 copies sold.

Minesweeper from pack 1 was later bundled with Windows 3.1, and FreeCell was included in Windows 95. WinChess and Taipei, both written by David Norris, received remakes in Windows Vista, called Chess Titans and Mahjong Titans, respectively. Mahjong Titans was replaced with Microsoft Mahjong in Windows 8. Microsoft Solitaire Collection also includes versions of Tut's Tomb (as Pyramid) and TriPeaks.

The Best of Microsoft Entertainment Pack is a collection of 13 games from previous Entertainment Packs. A Game Boy Color version was released in June 2001 in North America and August 2001 in Europe. It was developed by Saffire and published by Conspiracy Entertainment under the Classified Games label in North America and Cryo Interactive in Europe.

In 1997, Microsoft released a port of Entertainment Pack to its Windows CE mobile platform. It included the following games:

Three of these games (marked with * above) were unique to the Windows CE version. Three of the games (Hearts, Reversi and Sink the Ships) included multiplayer functionality between palmtops equipped with infrared ports .

Microsoft Entertainment Pack was designed by the company's “Entry Business” team, whose job was to make Windows more appealing to homes and small businesses. Ex-Microsoft product manager Bruce Ryan said the company did this because it "was concerned that the operating system’s high hardware requirements meant that people would only see it as a tool for large enterprises". The project had "almost no budget", and no major video game publishers got involved because they doubted Windows' legitimacy as a gaming platform; therefore Ryan compiled a series of games that Windows employees had been working on in their spare time. According to Microsoft FreeCell developer Jim Horne, the packs were not copy protected so customers could distribute copies to friends, to encourage using Windows for games. As payment, each author received ten shares of Microsoft stock.

For much of the early 1990s, the Gamesampler, a subset of the Entertainment Pack small enough to fit on a single high-density disk, was shipped as a free eleventh disk added to a ten-pack of Verbatim blank 3.5" microfloppy diskettes. Games on the sampler included Jezzball, Rodent's Revenge, Tetris, and Skifree. A "Best of" disk of several of the games was also available at times as a mail-in premium from Kellogg's cereals.