"They went ahead and did it without listening to anyone", a snitch dished to the outlet, adding Bieber, 24, and Baldwin, 21, were legally married at the courthouse and will throw a "big blowout" with friends and family in the near future.
TMZ reports the wedding celebration is happening "soon", potentially as early as next week in the singer's home country of Canada.
TMZ reported that the couple was seen at a NY courthouse, specifically at the marriage bureau.
Baldwin spoke about her upcoming marriage to Justin with The Cut, telling them, "I see no reason to wait".
The couple tied the knot on Thursday in New York City, People was first to report.
Not too long ago Hailey opened up to The Cut about what she wants her wedding to look like and she described "lights strung everywhere", detailing how "having it in the woods would be so attractive".
"Relationships at this age are already complicated", she told E!
"I think having it in the woods would be so attractive", she said. Guess we'll just have to wait until their second ceremony to see what Baldwin will really wear. Apparently, Bieber and Baldwin want to have a religious ceremony. "I think having it in the woods would be so lovely".
The Canadian crooner and the Arizona-born beauty - who got engaged on July 7 - previously dated off/on in 2015 and 2016, but they've been inseparable ever since June.