The 37-year-old singer posted a picture of him with his new son, Noah, and his wife on social networking website Instagram and said he was "overjoyed and filled with gratitude", reported Los Angeles, Times.
Noah was born in Buble's native Canada in Vancouver, British Columbia.
"Overjoyed and filled with gratitude at the arrival of our son Noah Buble. Born this morning, August 27 at 2:26am in Vancouver, Canada," Buble posted.
The new father accompanied the statement with a picture of the happy family. Tiny baby Noah, with a full head of hair, can be seen resting on his mother.
The couple announced they were having a baby in January of this year via a Youtube video and later announced they would be welcoming a son.
Buble and Lopilato have been married since March 2009. Lopilato is an Argentinian born model who has featured on Buble's music video for 'Haven't Met You Yet, a song he co-wrote for his then fiancee.