Bieber, 24, and Baldwin, 21, have not commented on the news, originally reported Sunday morning by TMZ.
Several news outlets, citing anonymous sources, appeared to back up the TMZ report of the engagement, which was reportedly announced Saturday night in the Bahamas.
"They are engaged and it happened Saturday night in front of a crowd in Baker's Bay," E! News reported.
Us Weekly, citing a source close to Baldwin, said that the model "is obsessed with Justin and always has been."
"It's kind of a surprise, but kind of not. Justin has been extremely happy these past few weeks," a source told People. "He has known Hailey for a long time. This might seem sudden, but they know each other very well."
Related: Photos: Justin Bieber through the years
Bieber and Baldwin dated previously before breaking up in 2016, Billboard reported. The couple apparently recently rekindled their relationship and was since dancing at a restaurant Friday, Billboard reported.
According to media reports, the singer of “Love Yourself” and “Where Are U Now” proposed to Baldwin in front of a crowd at a Bahama resort. Bieber’s security detail allegedly told the crowd to put their phones away “because something special was about to happen.”
Bieber’s father, Jeremy Bieber posted vague congratulations Sunday on Instagram, posting that he was “excited for the next chapter.”
Bieber's mother, Pattie Mallette, tweeted "Love Love Love Love Love Love Love."
Predictably, social media was abuzz with the reports: