The entertainer married music executive Tommy Mottola in 2000. They also are the parents of a 3 1/2-year-old daughter named Sabrina.
People.com said Matthew Alejandro Mottola was 7 pounds, 14 ounces when he was born Saturday.
"Good night! Matteo Alejandro and Mama are going to sleep! Thank you for your love and light!" Thalia said via Twitter Sunday.