Speaking to TMZ, the 18-year-old singer said that she believes in paranormal activity because of the childhood encounter.
"I've seen a ghost before, it was creepy. It was in my closet when I was about 8 and it scared me to death. It just popped out and it was horrible!"
Lovato, who recently returned to work after escaping the limelight to deal with "emotional and physical issues", is not the only celebrity to have reported supernatural experiences.
Lady GaGa was apparently followed around on tour by an angry spirit called Ryan, and organised a séance to rid herself of the "bad omen".
Meanwhile British TV presenter Holly Willoughby was cured of a ghost phobia by This Morning life coaches earlier this week.