Facebook users often ask about how to lock Facebook profile on iPhone. If you want to change your Facebook profile on iPhone or Mac device, here we will take you through the right process. First of all, open the Facebook app on your iPhone and visit your profile. Then, click on the three dots icon placed next to the +Add story option. Next, select the Lock Facebook Profile option and click OK. Thus, this is your guide to how to lock Facebook profile on Mac or iPhone.