Office Online，原称Microsoft Office Web Apps，是Microsoft Office套件的网页在线版本，包含有Microsoft Word、Microsoft Excel、Microsoft PowerPoint、Microsoft OneNote和Microsoft Outlook的网页版。这些网页应用使用户可以使用一个网页浏览器直接访问他们的文档，同时也支持文档分享和与其他用户在线协作。

Office Online (previously Office Web Apps) is an online office suite offered by Microsoft, which allows users to create and edit files using lightweight, web browser-based versions of Microsoft Office applications: Word, Excel, PowerPoint and OneNote. The offering also includes Outlook.com, People, Calendar and OneDrive, all of which are accessible from a unified app switcher. The on-premises version of this service called Office Web Apps Server can be installed in private clouds in conjunction with Microsoft SharePoint, Microsoft Exchange Server and Microsoft Lync Server.