Facebook doesn't provide a direct notification or definitive way to check if someone has blocked you. However, you can use indirect methods to identify a block. Try searching for the person's profile by name—if you cannot find them and previously could, they may have blocked you or deactivated their account. Visit your previous conversations with them; if their profile no longer appears clickable or shows as unavailable, that's another sign. Check if you can view their profile through a mutual friend's friend list; if they appear there but you cannot access their profile directly, you're likely blocked. You can also try visiting their profile URL directly if you remember it—a blocked profile typically shows a message like "User Not Found" or "The link you followed may be broken." Important distinctions: blocking is different from unfriending (unfriended people's profiles are still viewable) or deactivating (their account temporarily disappears). Note that if someone has set strict privacy settings, their profile might appear limited without necessarily blocking you. If you suspect a block and it matters significantly, the most straightforward approach is to ask the person directly or use a mutual friend to inquire. Facebook prioritizes user privacy, so the platform intentionally doesn't make blocks obvious to prevent confrontation.