Can I stop someone from leaving comments on my blog?

Your WordPress.com blog has several features that you can use to restrict or block people from leaving comments.

1. Only allow comments by logged-in WordPress.com users

On the Settings > General tab of your dashboard, you’ll find a check box that says “Membership: Users must be registered and logged in to comment.” Check this box and click the Save Changes button. This will require people to log in to WordPress.com before they can leave a comment on your blog.

2. Require administrator approval of comments or comment authors

On the Settings > Discussion tab of your dashboard, you’ll find three check boxes under the heading “Before a comment appears.”

Check the first box, “An administrator must always approve the comment,” to turn on comment moderation. This means comments must be approved by you before they will become visible on your blog.

Check the second two boxes, “Comment author must fill out name and e-mail” and “Comment author must have a previously approved comment”, to simplify the moderation process. If these boxes are set, you need only approve each comment’s author once - subsequent comments by the same author will automatically be approved. We recommend using this option in conjunction with the “Only allow comments by logged-in WordPress.com users” setting, as above.

3. Blacklist certain words or comment authors

Under the “Comment Moderation” and “Comment Blacklist” headings, you’ll see two text boxes. You can enter names, URLs and key words in those boxes to restrict or prevent comments that contain those things.

The Comment Moderation box will cause comments to go to the moderation queue for your approval. The Comment Blacklist box will cause comments to be prevented altogether. You can use these two boxes in conjunction with the “Only allow comments by logged-in WordPress.com users” setting to restrict or block comments by a specific author by entering their username or email address.

4. Use Akismet

On the Comments tab of your dashboard, you’ll see a list of the comments on your blog, along with options for deleting them or marking them as spam. Click the “Spam” link to remove advertising and other bulk comments.

Please note that we normally cannot block IP addresses from posting comments. Doing so might block genuine users of WordPress.com.

If someone is repeatedly leaving unpleasant comments, the first thing you should do is make sure that all comments are moderated. This stops someone from seeing their comment and from others seeing it too.
You should also delete all such comments but make no mention of what you are doing. If you do it will just encourage more unwelcome comments.

5. Turn off comments for individual post

While writing a post, scroll down to Advanced Options and uncheck the ‘Allow Comments’ under the Comments & Pings section.