How to Sort WordPress Users By Registration Date
Sorting users by registration date can come in handy, especially in terms of being able to manage and delete spam users. This is something I’d love to see added to the WordPress core for single site installations. For now you can get this in a plugin called Recently Registered. The plugin works just like it does on WordPress multisite, only it’s made for single site. It offers a new, sortable, column within your users lists, showing the date they registered.
Please note that you do NOT need this plugin if you have WordPress multisite active, as it already provides this. Once you have the plugin activated, go to your Users page and pull down the Screen Options to select Registered. You can now sort by registration date. Download the Recently Registered plugin from the WordPress plugin repository.