The supermodel has previously spoken about why women might find the comedian attractive.
"Pete and Emily have known each other for a while because they run in similar circles. They've always had a good time together and liked each other," says the source. "More recently, they have spent one-on-one time with each other and things have become flirtatious between them. Emily is playing the field and enjoying dating."
Us Weekly was the first to report the news, and ET has reached out to reps for Davidson and Ratajkowski.
Meanwhile, Ratajkowski filed for divorce from Sebastian Bear-McClard in September and has since been romantically linked to Brad Pitt and DJ Orazio Rispo. However, in October, Ratajkowski referred to herself as "newly single" in an interview with Variety amid the romance rumors.
"I’m newly single for basically the first time in my life ever, and I just feel like I’m kind of enjoying the freedom of not being super worried about how I’m being perceived," she said.
Davidson and Ratajkowski have a history together. While Davidson was still in a relationship with 42-year-old Kardashian, Ratajkowski publicly defended the Meet Cute star during a November 2021 interview on Late Night With Seth Meyers. Ratajkowski and Davidson had worked on a photo shoot together and she referred to him as "a professional," adding, "I was impressed."
She also weighed in on Davidson's charm, discussing why women find him attractive.
"He's got the height, obviously women find him very attractive," she said, adding of those questioning the Saturday Night Live alum's appeal, "I feel like only other men feel that way. Guys are like, 'Wow, what's that guy got?' He seems super charming, vulnerable, lovely. His fingernail polish is awesome. He looks good! Good relationship with his mother, we love it!"
Ratajkowski also has a history with Kardashian. In 2016, the pair posed topless together in a mirror selfie, flipping off the camera after Piers Morgan had publicly insulted Kardashian for a nude pic. Ratajkowski defended the mother of four on Twitter and then posed alongside her for the headline-making image.
"Kim was kind enough to send me flowers," Ratajkowski told The Evening Standard Magazine at the time. "Then we decided to do a selfie with our tops off, flipping off the camera, which I think speaks for itself."
Last month, a source told ET that Davidson and Kardashian have remained friendly since their split.
"Pete and Kim still keep in touch," the source said. "It wasn't a bad fallout or breakup, so things are good between them and they've remained in contact."