Miranda Kerr has given birth to a baby boy.

The 40-year-old model has taken to Snapchat to reveal that she's given birth to her fourth child, and her third with her husband Evan Spiegel.

Alongside a photo of flowers, nestled next to a pair of baby socks, Miranda wrote: "We are overjoyed to announce the arrival of our little ray of sunshine, Pierre Kerr Spiegel. We couldn't be more excited to welcome our fourth son into our family. Feeling so very blessed. [prayer, child, rainbow and flower emojis] (sic)"

Miranda also has Myles, four, and Hart, five, with her husband, as well as Flynn, 12, with actor Orlando Bloom.

The model - who has been married to Evan since 2017 - actually announced her pregnancy on Snapchat back in September.

The brunette beauty wrote at the time: "So excited to announce baby no. 4. And it's a boy [heart emojis] (sic)"

Miranda previously revealed that she loves the challenge of motherhood.

She told Vogue Australia last year: "I just love being a mother and I always wanted three boys, so I feel really blessed that I have three healthy boys."

Miranda also revealed that she was "open" to the idea of having another baby.

Asked about the possibility of having another child, she replied: "I feel like I’m open, so we’ll see what God decides."

Despite this, Miranda acknowledged that motherhood isn't easy.

The model admitted that herself and Evan - who is the CEO of Snap Inc, the developer of Snapchat - only get around "six to seven" hours of sleep a night because of their kids.

She shared: "There’s [usually] at least one of them up at night, or sometimes all three if we get unlucky.

"We try to get eight hours sleep, but we probably get around six to seven."