On Tumblr, you can’t set up your primary blog as private or prevent blog visitors from viewing public posts. You also can’t block specific people from seeing individual posts on a post-by-post basis. Instead, the block list blocks a user from interacting with you. Tumblr refers to its block list as the Ignored Users list.

Benefits of Blocking Users

When you ignore a user on Tumblr, he can no longer follow you or see and track your direct posts through his Dashboard. On your end, you don’t have to deal with any messages from the user. Additionally, he won’t appear in post notes or Dashboard notifications.

Accessing the List

To access the list from your Following page, click “Following [Number] Blogs” in the Account section on the Dashboard sidebar, find the “If you need to, you can ignore users” and click the “ignore users” link. To access the list from your Account settings page, click the gear icon on your Dashboard and then click the “Ignored Users” button. Lastly, to access the page directly, open a new browser tab, type “tumblr.com/ignore” in the address bar and press the “Enter” key.

Warnings

A blocked user can still see some of your content on his Dashboard if he follows another Tumblr user who has access to your posts and reblogs them. Information in this article applies to Tumblr as of January 2014. It may vary slightly or significantly with other versions or products.