Yes, you can turn off Who's Viewed me, and people will NOT know when you view their profile. But, you will ALSO not know when people view your profile, which is incentive for most people to keep it on.
In the top nav bar, click on the "Profile" dropdown. It will expand.
Click on the ( Menu) icon on the top right corner of the page. The menu will expand.
Then click on the dropdown that says "My Profile". It will expand.
Then click on Edit Settings in the list of links.
Then click on the Edit Who's Viewed Me Settings link
Click the radio button that says "Turned Off", and click the "Save Changes" button.