The actor's wife Genevieve has given birth to the couple's first child, he announced on Twitter today.
Writing on the social networking site, Padalecki said: "It's a boy :)"
Jared and Genevieve Padalecki announced in October that they were expecting their first child, before confirming in November that it would be a boy.
The couple met on the set of Supernatural when Genevieve starred in the show as Ruby.
They announced their engagement in January 2010 before tying the knot in March 2010.