Little Sadie Grace LeNoble was born Jan. 27, and the first-time mom and baby are both doing great, said Applegate's publicist.
The proud papa posted the news on his Facebook page late Monday. The 41-year-old Dutch musician said Sadie Grace weighed in at 7 pounds and 8 ounces.
Applegate, 39, welcomes her baby two years after overcoming breast cancer.
Applegate and LeNoble announced their engagement last Valentine's Day.
The Associated Press contributed to this report.