Microsoft Office is a suite of productivity programs created by Microsoft and developed for Microsoft Windows and Apple Macintosh operating systems. As well as the office applications, it includes associated servers and Web-based services. Recent versions of Office are now called the 'Office System' rather than the 'Office Suite' to reflect the fact that they include Servers as well.

Office made its first appearance in the early '90s, and was initially a marketing term for a bundled set of applications that were previously marketed and sold separately. The main selling point was that buying the bundle was substantially cheaper than buying each of the individual applications on their own. The first version of Office contained Word, Excel and Powerpoint. Additionally, a "Pro" version of Office included Microsoft Access and Schedule Plus. Over the years the Office applications have grown substantially closer together from a technical standpoint, sharing features such as a common spell checker, OLE data integration and the Microsoft Visual Basic for Applications scripting language. In recent years, Microsoft has attempted to position Office as a development platform in its own right, but has had mixed results with this.

Office is currently the most popular office suite in the world and considered to be the de facto standard for productivity programs, although its market share is currently decreasing with the rise of viable free and open source alternatives. It has certain features not present in other suites, and other programs have capabilities Office lacks. Office 2007, which was officially announced on February 16, 2006, will have a radically different user interface from the older versions.