How to Stop Someone From Sending a Friend Request on Facebook
- 1). Log in to your Facebook account.
- 2). Click on the downward-facing arrow beside "Account" in the top-right corner of the page.
- 3). Click on "Privacy Settings" in the drop-down menu.
- 4). Click on the blue "View Settings" link at the top of the page, under "Connecting on Facebook."
- 5). Click on the downward-facing arrow beside "Send you friend requests."
- 6). Click on "Friends of Friends" in the drop-down menu.
Source...