A Google Calendar attachment can give guests access to an agenda, spreadsheet, or supporting file. The file remains a Drive resource with its own permissions. Review both the attachment title and its sharing scope before adding it to an event with a broad or mixed audience.
Add the intended file
On a computer, create or edit the event and open More options when necessary. In the description area, use Add a Google Drive attachment. Select an existing Drive file or use Upload for an authorized local file, then complete the selection.
Check the audience implications
Google’s guidance says attachment names are visible to invited guests and people with access to event details. A restricted file can therefore reveal its title even to someone who cannot open its contents. Use an appropriate file and filename for that audience.
When saving, inspect any sharing prompt rather than accepting broad link access by habit. The event’s guest list and the file’s access rules are separate.
Verify the recipient route
Reopen the event and confirm the correct file is attached. Test access through a representative intended guest when appropriate, with the least permission needed. If Drive is disabled by an organization, involve the administrator instead of bypassing the restriction with an unrelated public upload. A visible attachment is not proof that everyone can open it, and a file that opens for the organizer is not proof that the same route works for external guests. Check the actual final file before sharing sensitive material.
References
Reviewed against the linked official product guidance on November 4, 2026. Features, limits, screen labels, and access can vary by account, platform, region, and organization policy.