Lets say you have an requirement to add a lot of security groups to Site collection administrators especially when you are having multiple regional SharePoint sites in Office 365.

To do it, in the site collection you want to manage, click gear icon  > Site settings > Users and Permissions > Site collection administrators. Add the Office 365 groups you want here.

In order to create a new office 365 group , please follow the below steps in your office 365 environment.

1. ClickDashboard > Groups.
2. On Groups page, click Add . The Create security group wizard appears.
3. Type a name and description for the group, and then click Create.
4. To add members to your new group, click Edit members

The groups created can be part of SharePoint Site collection administrators. Happy SharePointing 🙂