SharePoint Permissions – Access for everyone?

We are currently migrating our intranet to a SharePoint based intranet. What we would like to do is add a URL into the older intranet linking to the new SharePoint so users across multiple departments can access and test the site before we go into production.

Is there any way for everyone based in our organization to view this site without having to accept manual permissions for every single user? We are using SharePoint Online.

Thank you for your time