Hailee and Niall were reportedly friends before they began dating; in a December 2017 Instagram post, he wished her a happy birthday and called her "the loveliest person on the planet and one of my best friends." By February 2018, they were spotted by People on a date night, and from there, they were often seen together, although rarely showing up at formal events as a couple.
They were seen at a Backstreet Boys concert, at music events, and at casual dinners, among other sightings throughout 2018. In an interview with Cosmopolitan, Hailee talked about falling in love, though without ever mentioning anyone by name.
"When you fall in love, you pick up on the tiniest things about yourself. I am one to spread out on the mattress and take up every inch of space. Now I don't want to do that anymore. I want to make as much room for you as possible."
However, it wasn't to last. In December 2018, Entertainment Tonight confirmed their split. Since then, Hailee has not been linked to anyone.