US Weekly reports the young stars have split after more than one year of dating.
The Call Me By Your Name star appeared alongside Depp (the daughter of actor Johnny Depp) in the film, The King.
They were first linked romantically in 2018, when they were seen making out in New York, and shortly after they vacationed together in Paris, France.
The two were last photographed kissing passionately on a boat in Capri, Italy, in September.
The following month, Depp, 20, told ET she had been nervous working alongside “incredible” Chalamet in The King.
“It's always exciting to work with somebody who you know has given themselves so wholeheartedly to their role and is so invested,” she said. “It can be nerve-wracking to work with people whose talent you admire so much, but hopefully it can only make things better.”
Chalamet meanwhile told ET he wasn’t bothered by receiving increased paparazzi attention -- likely due to the rumored romance.
See more on Chalamet and Depp below.