The 26-year-old posted a photo of she and Adams, 33, lying in bed with the Nashville DJ's Snapchat-famous dog Carl.
"[Spoon]ing," she captioned the picture.
The two have been rumored to have been seeing each other for a while now, engaging in flirty banter on Twitter and dropping hints on social media that they've been involved.
On Halloween, the two dressed as the characters Dustin and Eleven from Stranger Things, and captioned the photo "#strangerthings have happened."
Since then, the two have been on each other's Snapchat stories constantly showing Hyland visiting the Bachelor in Paradise bartender in his hometown of Nashville and Adams traveling to Los Angeles to visit the actress.
Adams all but confirmed his relationship with the Hair alum on The Morning Breath last week, saying, "To be fair, if you want to know anything, just look on my social media."
Prior to Adams, Hyland dated British actor and model Dominic Sherwood for more than two years. The couple broke things off in August in an amicable split.
Adams, meanwhile, sparked rumors of a romance with close friend Danielle Maltby last season on Bachelor in Paradise, but has been clear that nothing came of the on-screen kiss.