The soft, piano-backed melancholic track sees the Canadian star talking about the end of a turbulent relationship. Prior to the release, Mendes teased the song on Tuesday.
He took to his Instagram account to share a 12-second snippet of the melody. "it'll be okay, tomorrow 12/1 7pm EST," he wrote in the caption. Fans were beyond excited over the new single.
"I know this is gonna hurt so bad," one fan wrote. While another said: "Heartbreak era."
The breakup song arrived just two weeks after Mendes and singer Camila Cabello announced their split after dating for two years.
In a joint statement shared on their respective Instagram accounts, the former couple said: "Hey guys, we've decided to end our romantic relationship but our love for one another as humans is stronger than ever."
The 'Senorita' collaborators then assured fans that they will continue to be best friends despite calling it quits. "We started our relationship as best friends and will continue to be best friends. We so appreciate your support from the beginning and moving forward," the statement read.