Kris Allen and Katy O'Connell

American Idol winner Kris Allen is a dad!

Allen and his wife, Katy O'Connell, welcomed a baby boy named Oliver on Tuesday. "Happy Day!!!! My little stud was born today. Oliver is here people!" Allen, 28, tweeted Tuesday night.

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The singer also posted a picture of himself in hospital scrubs on Instagram with the caption, "My outfit for the day. The best outfit ill ever where [sic]. #bestdayofmylife."

Allen and O'Connell are high school sweethearts and have been married since 2008.