Importing an .ics file into Outlook on a Mac
When you open an .ics calendar event file on a Mac computer, it will likely add the event to the MacOS Calendar app instead of your Outlook calendar. This is how to get that .ics event file into Outlook.
If you only use Outlook, you should consider changing the .ics file association so that opening any .ics file will add the event to Outlook (essentially skipping to step 4 below). Instructions available at
Instructions
Save the .ics file to your computer instead of opening it. If it was received as an email attachment, click the option bar to the right of the file and select Save As…
Open your calendar in Outlook
Use Finder to locate the saved/downloaded .ics file and then drag and drop it onto the calendar
An Add Event import dialog will appear (below). Confirm that your work calendar (usually labelled just “Calendar”) is the one that is selected as the target and click Import
A confirmation dialog will appear (below).
At this point you can click Done or View Event to see it in your calendar (below)