No — adding someone on Instagram does not automatically add them on Facebook. The two apps are linked only if you set up sharing or account-center options, and even then that usually affects posts or profile connections, not an automatic friend add.

What actually happens

  • If you follow someone on Instagram, that does not create a Facebook friend request.
  • If your Facebook and Instagram accounts are connected, you may see options to share content across both apps, but that is separate from adding people as friends.
  • Some settings can make Instagram posts or stories share to Facebook automatically, but that is about content sharing, not adding accounts.

Simple example

If you follow a friend on Instagram today, they will only be added on Instagram unless you separately add them on Facebook yourself.

TL;DR

Instagram follows and Facebook friends are different, so one does not automatically create the other.