See "What version of Office am I using?" if you don't know what version you're on.
Version of Office
15.35 and later
Office 2016 for Mac is fully supported on macOS 10.13 High Sierra.
If you encounter issues using Office 2016 for Mac, please send us feedback so we can address them. In Word, Excel, PowerPoint and OneNote, you can click on the Send a Smile icon in the top-right of the app. For Outlook, choose Contact Support from the Help menu.
15.34 and earlier
These versions are not supported on 10.13. In some cases, you may not be able to launch the Office apps. For example, users will see the following error message when attempting to launch Outlook 2016 ver. 15.34:
If you installed Outlook 2016 ver. 15.34 or earlier, and are not being offered an update to 15.35 or later, download the latest Office 2016 for Mac Suite Installer here.
Office for Mac 2011
Word, Excel, PowerPoint, Outlook, and Lync have not been tested on macOS 10.13 High Sierra, and no formal support for this configuration will be provided.
Since October 10, 2017, Office for Mac 2011* is no longer supported. This means there will be no new security updates, non-security updates, free or paid assisted support options, or technical content updates. Refer to the Microsoft Support Lifecycle for more information.
* Lync for Mac 2011 has a limited time of Extended Support for security fixes.