You cannot see exactly who viewed a regular Instagram post
Instagram does not provide a viewer list for feed posts
You can see the total number of likes and comments on the post
You can see who liked the post by tapping the like count
You can see who commented on the post by opening the comments
For Instagram Stories, you can see who viewed them
For Instagram Reels, you can see total views and interactions, but not a full viewer list
For Instagram Live, you can see some viewers while live
For professional accounts, you can view post insights such as reach, impressions, and engagement
Avoid third-party apps that claim to show post viewers