The new father announced the birth of his son on Twitter with a sweet photo of the newborn.
Eric's older brother Donald Trump Jr, who has five children, teased his sibling: "Congrats buddy".
"Eric's dad was so excited that we were anxious he'd blurt it out at a press conference", Lara Trump told People.
Lara is a former "Inside Edition" producer now involved with multiple animal charities, while Eric is an executive vice president of the Trump Organization.
Eric, 33, President Trump's 2nd son and third child took to Twitter on Tuesday to announce that Lara, 34, had given birth.
This is Eric and Lara Trump's first child and Donald Trump's ninth grandchild.
Eric Trump declared the birth before Tuesday through Twitter.
And Aunt Ivanka Trump wrote, "Welcome to the world, baby boy".
Ivanka Trump, who has three kids with husband and fellow White House adviser Jared Kushner, also offered her congratulations. "I can't wait to meet you".