"Do I think they’re dating? Yes," she told Entertainment Tonight.
Photos of the two surfaced last week, showing Styles and Jenner relaxing together in St. Barts on New Year's Eve.
"But ... I don't know if they're like boyfriend-girlfriend," Kardashian added. "Nowadays I don't know, people are weird with stuff. So, I don't know their title. But I mean, they were in St. Barts together hanging out, so to me that's dating."
A rep for both Jenner, 20, and Styles, 21, didn't immediately respond to ABC News' request for comment.
Khloe didn't mince words and continued, saying, "I would call [the trip together] dating ... But, you know, you have to have 'the talk' [and] I don't know if they've had that talk yet ... you need the talk, I don't believe in just assuming what you are."
This isn't the first time Styles and Jenner have hung out. In 2013, the two were spotted having dinner together.