Nick Heidfeld’s third child was born on Monday night.
The Mercedes reserve driver, who is believed to be testing new F1 supplier Pirelli’s tyres at Mugello on Tuesday and Wednesday, said the baby boy has been named Justus.
"We are all well," the 33-year-old German said on his website.
With his partner Patricia, Heidfeld lives in Switzerland along with daughter Juni (4) and son Joda (2).