How to delete a comment on Instagram that someone else wrote on one of your posts
1. Open the Instagram app on your iPhone or Android and log in to your account.
2. Tap your profile icon in the bottom-right corner of the app to go to your profile.
3. Find and select the post you want to delete a comment on.
4. Tap on one of the comments on your post, then on the Comments summary page, tap the icon of three horizontal dots in the top-right corner.
5. In the pop-up, select Manage Comments.
6. A circle will appear next to each comment — tap the circle next to the comment(s) you want to delete, making a checkmark appear. Then, tap Delete at the bottom-left of the page.
7. Choose Delete Comment in the pop-up, and the comment will be immediately deleted.