The 23-year-old "Cool for the Summer" hitmaker took to Instagram to unveil the body art on the top third of her finger.
"Cause life's too short not to tattoo your pinky," she captioned the picture.
She posted another photo featuring her in a ripped, black-and-white striped tee and jeans.
Lovato has more than 25 works of body art, including the words "You Make Me Beautiful" across her rib cage, 12 birds flying up one arm which represented the 12 steps she completed post-rehab, and "Stay Strong" on her wrists.