The eighth-season American Idol winner and his wife Katy O'Connell welcomed a baby boy into the world on Tuesday.
"Happy Day!!!! My little stud was born today. Oliver is here people!" Allen tweeted yesterday.
Allen's representative also confirmed the good news.
"Little Oliver Neil Allen is here!" the representative toldUs Weekly. "He's 7 pounds, 7 ounces, 20 3/4 inches long. Mom and baby are doing great."
Allen revealed the couple was expecting their first child together in January as part of an announcement that he and O'Connell were okay following a head-on collision car accident they got into on New Year's Day.
Although both Allen and O'Connell were injured, everyone in the vehicle -- including the unborn child and the couple's dog Zorro -- was safe.
"Yes I got in a really bad wreck tonight and yes I'm having a lil baby," Allen tweeted at the time.
Allen and O'Connell were high school sweethearts who married in 2008.