To make your friends list private on Facebook, follow these steps: On Desktop:

1. Log in to Facebook.com.
2. Click your profile icon in the top-right corner.
3. Select Settings & Privacy, then click Settings.
4. In the left sidebar, click Privacy.
5. Scroll to the How People Find and Contact You section.
6. Click Edit next to Who Can See Your Friends List?
7. From the dropdown menu, select Only Me to make your friends list completely private. You can also choose other options like Friends , Specific Friends , or Friends Except... if you want to limit visibility more selectively.
8. Click Save or Done to apply the changes

On Mobile (Facebook App):

1. Open the Facebook app on your iPhone or Android device.
2. Tap the menu icon (three horizontal lines).
3. Scroll down and tap Settings & Privacy, then Settings.
4. Scroll to Audience and Visibility , then tap How People Find and Contact You.
5. Tap Who Can See Your Friends List?
6. Choose Only Me to hide your friends list from everyone except yourself, or select other privacy options as desired.
7. Confirm your selection to save the changes

This setting ensures that no one else can see your full friends list, enhancing your privacy on Facebook. Note that mutual friends may still be visible to others even if your friends list is hidden