Benjamin Roethlisberger Jr. arrived Wednesday at 10:06 p.m., according to the athlete's website. The couple's first child weighed 7 pounds, 1 ounce, and was just over 19 inches long.
The quarterback posted Thursday that mother and baby boy were doing well.
"We want to thank everyone for their thoughts and prayers, it really means a lot to us. God is so good!" he wrote.
Roethlisberger made an appearance Thursday at a team facility in Pittsburgh, smiling and waving to a well-wisher who congratulated him as he left practice about 30 minutes early. He had previously been scratched from Sunday's game against Cleveland because of rib injuries.
Offensive lineman Willie Colon said afterward that Roethlisberger "came in with that big old proud papa chest."
Teammate Max Starks said that the quarterback seemed very excited - and that he knows the feeling, since his first child, a girl, was born three weeks ago.
"I have no advice for him. I'm still working my way through it," the offensive lineman said with a laugh. "Just try and sleep when you can."
Roethlisberger's website says he'll post pictures this weekend.