You will need a valid product key from a legacy purchase. Limitations of Office 2011 in 2026 No Further Updates: Microsoft closed all support years ago.
For users who absolutely must run a modern, supported version of Microsoft Office, the most reliable option is to circumvent OS X Lion entirely.
Installation Tip: After installing Office 2011, you must download the "Office 2011 14.7.7 Update." This was the final update ever released and fixes many bugs that existed in the base 14.0.0 version. The Modern Workaround: Office Online
If you are using an older Mac that is still running OS X Lion in 2025/2026, your situation is highly unusual. Most software has moved on. Here are your realistic paths forward: microsoft office for mac os x lion 1075 2021
Running Microsoft Office on Mac OS X Lion in 2021 is for daily use. Office 2011 is fragile, unsecure, and may stop activating at any time. If you must keep Lion, switch to LibreOffice 5.4 or use a modern computer for any critical collaborative document work.
If you attempt to install a version of Microsoft Office released around 2021 (such as Office 2021 or Microsoft 365) on OS X Lion, the installation will fail.
Google Docs, Sheets, and Slides run entirely in the browser and offer flawless collaboration. You will need a valid product key from a legacy purchase
Compatibility: Works well, though the interface feels more dated.
Under the tab, look for the option labeled Allow apps downloaded from .
With the end of support for Office 2016 for Mac occurring on October 13, 2020, it is officially an unsupported product on any system, including unsupported operating systems like OS X Lion. Installation Tip: After installing Office 2011, you must
It fully supports .docx , .xlsx , and .pptx file formats, keeping you compatible with modern file types.
In 2021, Microsoft’s online activation servers for Office 2011 may fail to recognize your key or refuse the connection due to outdated security protocols on OS X Lion. If online activation fails, you must use the telephone activation option provided in the activation wizard to complete the setup. Essential Updates and Patches
关键是要理清三个部分：旧系统OS X Lion（10.7）对应的Office版本、2021年时对旧系统的支持情况，以及“1075”这个数字可能指代什么。如果它是打印错误或内部版本号，也需要说明。
If you can find older versions of Apple’s productivity suite (e.g., iWork '09), they are highly compatible with Lion. Essential Tips for Old Mac Maintenance
It included Word, Excel, PowerPoint, and Outlook (for Home & Business editions). End of Support: