Visual Basic for Applications (VBA) is an implementation of Microsoft's Visual Basic, an event driven programming language and associated integrated development environment (IDE) which is built into most Microsoft Office applications. It is also built in to Office applications for Apple Mac OS, other Microsoft applications such as Microsoft MapPoint and Microsoft Visio — a former independent application which was acquired by Microsoft — as well as being at least partially implemented in some other applications such as AutoCAD, WordPerfect and ESRI ArcGIS. It supersedes and expands on the capabilities of earlier application-specific macro programming languages such as Word's WordBasic, and can be used to control almost all aspects of the host application, including manipulating user interface features, such as menus and toolbars, and working with custom user forms or dialog boxes. VBA can also be used to create import and export filters for various file formats, such as ODF.

VBA itself is an interpreted language. As its name suggests, VBA is closely related to Visual Basic, but can normally only run code from within a host application rather than as a standalone application. It can, however, be used to control one application from another using OLE Automation. For example, it is used to automatically create a Word report from Excel data, in turn automatically collected by Excel from polled observation sensors.

VBA is functionally rich and extremely flexible but it does have some important limitations, including limited support for function pointers which are used as callback functions in the Windows API. It has the ability to use (but not create) (ActiveX/CO M) DLLs, and later versions add support for class modules.