A person someone loves most above all things.
They probably won't tell anyone who their Favorite Person is but when around their FP, it's like every fear and insecurity fades away and you're left with the best thing in the whole world
Someone: "Oh yeah they're my FAVORITE PERSON. And I love them with all my heart"
A favorite person is someone that a person with a mental illness will rely on for support and often looks up to or idolizes them. It’s most common with people who have borderline personality disorder (BPD) to have a FP and they usually only have one, but some people can have many.