Kroes' new husband, DJ Sunnery James, delivered the good news in a series of tweets that included the little boy's name, Phyllon.
"We're in love with him. Can't describe the feeling. Phyllon (Pronounce: Fillen) is in our life," James tweeted.
James followed with a tweet that will resonate with new parents anywhere: "Thanks for all the love Getting some sleep :). Peace."
The Dutch-born Kroes, 25, married James in an intimate ceremony before 30 family and friends in Spain in Nov. 2010.
Little Phyllon's birth is perfectly timed to organize an age-appropriate playgroup with Kroes' fellow Victoria's Secret lovely, Australian model Miranda Kerr. Kerr gave birth on Jan. 6 to baby boy Flynn, her son with actor-husband Orlando Bloom.
Kerr recently shared a Bloom-shot picture of her contentedly nursing her beautiful son, who weighed in at almost 10 pounds, on the blog of her natural skincare line, Kora Organics.
Kerr and Kroes now join a sorority of Victoria's Secret pros who have become model moms recently including Heidi Klum, Audriana Lima and Alessandra Ambrosio.
Meanwhile, shoe and jewelry designer and all-round mogul-ette Ivanka Trump took to Twitter today to announce her own baby news: "I have been wanting to share some amazing news with you all for some time... I'm pregnant! Jared and I couldn't be more excited."
It will be the first child for Donald and Ivana Trump's daughter and her husband, businessman Jared Kushner.
Also, read about Natalie Portman and Jane Krakowski showing off their baby bumps at the 2011 Golden Globes.
And see the latest supermodel to announce her pregnancy.