Let's overlook the minor detail that they're both starring in a film together and this just may be a handy way of getting said film's name out there... OK? Let's just take off the cynical cap and just go with the idea that they actually find each other attractive.
The model - who has been linked to the likes of Harry Styles and Jake Bugg in the past - met the 24-year-old on the set of forthcoming movie, Tulip Fever, in which they both star.
An insider told The Sun: "Jack and Cara get on really well. So far their relationship is very casual but she's a big fan of him... They've been on a few dates and been seeing each other quite often but it's not yet serious. They met on the Tulip Fever set and hit it off immediately. They are both very busy all the time with work but they could make it work." Especially for the benefit of the promotional tour.
The 22-year-old bisexual model split from Michelle Rodriguez in May, while Jack - who you may recognise as that lad off Skins - dated Tulisa Contostalvos in 2012.
Meanwhile, Cara - who has just unveiled her new capsule fashion collection entitled Cara Delevingne for DKNY - claimed recently that self-confidence is a very attractive trait.
She explained to Glamour: "Well it's not about what you wear it's about how you're wearing it. Self confidence is the most important component in fashion."