Creating a SharePoint Online sub-site
Posted by Erin Bard on 28 January 2019 02:58 PM
Please note that SharePoint Online on Office 365 is a constantly evolving product and this guide may not reflect the current experience.
This guide will show you how to create a new sub-site on your Office 365 site.
Step 1. On your site, click on the gear icon in the upper-right corner.
Step 2. Select "Site Contents" from the drop down menu.
Step 3. On the site contents page, select the "Subsites" tab to see all the sub-sites already created for your site.
Step 4. To create a new sub-site, click on the "New" button.
Step 5. Then select "Subsite" from the dropdown meny that appears.
Step 6. On the next page that loads, provide a title for your site (this will be visible in multiple places). Also provide a URL path for your subsite, this needs to be one string of characters with no spaces or odd symbols.
On the same page, also select the radio button that says "Use unique permissions". You may also want to enable the option "Display this site on the Quick Launch of the parent site", which will add the site to the navigation menu on the left-side of your site. When ready, press "Create" at the bottom of the page.
Step 7. On this next page you'll be prompted to create your new unique permission groups. They should have appropriate names to begin with (in the format of "<Site Title> Visitors", "<Site Title> Members", and "<Site Title> Owners" where <site title> is the name you gave to your site on the previous step). You can change the names if you want, but we recommend keeping the default names to make it easier to communicate which is which if you are following guides or receiving assistance.
At this stage you can also add people to each of the groups in the highlighted boxes. Start typing someone's name and the system will attempt to auto-resolve the name to an account, select the correct name from the drop-down boxes that appear. You can also select the little book icon to locate someone from the address book, or press the button that looks like a person with a checkmark and it will attempt to resolve the names all at once (useful if you copy and paste multiple names into the box at once - separate names with a semi-colon).
When you are done press "OK" to proceed. The sub-site will then be created, and you will be taken to its home page. You may then interact with it just as you would any other SharePoint site.