Justin Bieber is a big brother once more, this time to a newborn baby sister.

Bieber's 43-year-old dad, Jeremy, announced the birth of his and new wife Chelsey Robelo's first child together, a daughter named Bay, on Thursday (August 16).

The couple debuted their bundle of joy in a sweet Instagram photo that showed Robelo and Bieber cuddling their little girl in the delivery room.

"Just welcomed a beautiful baby girl into the world. Bay Bieber #babygirl #biebergirl," Bieber tweeted this morning.

Bieber and Robelo announced they were expecting a child together back in February just days after getting married in a destination wedding in Jamaica, which Justin attended with his ex, Selena Gomez.

Bieber's other children, aside from Justin and Bay, include Jaxon, 8, and Jazmyn, 10.

Robelo has another daughter, Allie, from a relationship prior to Bieber.