Lionel Richie
The legendary singer took in Nicole Richie when she was just four years old and officially adopted her age nine. At the time Nicole's parents were experiencing personal and financial difficulties and couldn't provide for Nicole. Lionel - who has biological kids Sofia and Miles - instantly considered Nicole a part of his family.
He said: "So it took about maybe a year for me to just fall in love and she was a little button, and of course by that time I was 'Dad.'"