When you delete an organization, all repositories, forks of private repositories, wikis, issues, pull requests, and Project or Organization Pages are deleted as well.
1. Back up your organization content
Once you delete an organization, GitHub cannot restore your content. Therefore, before you delete your organization, make sure you have a copy of all private repositories, wikis, and issues from the account.
2. Delete the organization
In the top right corner of any page, click your username.
On the left side of your profile page, under "Organizations", click the icon for your organization.
To the right of your organization name, click .
Near the bottom of the organization's settings page, click Delete this Organization.
