The Celebrity Apprentice star confirmed on Sunday (October 21) on Twitter that Vanessa has given birth to a baby boy.
"It's a BOY!!! @MrsVanessaTrump and baby are doing great," Trump tweeted.
Vanessa previously revealed that she and Donald Jr were very "excited" to welcome their baby son.
"We're so blessed to be able to have another child to add to our happy, growing family," she said.
The couple are also parents to 5-year-old Kai and 3-year-old Donald III.
Donald Jr is expected to return for the upcoming all-star season of The Celebrity Apprentice, premiering in March on NBC.