Lovato, 20, opened up about her feelings for the newly-single Irish star, prompting gossips to hint that a new celebrity romance is brewing, reported Daily Star.
"All of the One Direction guys are great, but there is something a little special about him. Niall is really one of the most fun people to be around," she said.
Lovato also said she has been spending time with Horan in London as she recovers from a broken leg.
"I know when a text comes through from Niall there is a great chance it is going to actually make me laugh out loud," she said.
Horan is reportedly single after splitting from his drama student girlfriend Amy Green.