Sacks was born to a Jewish family in Cape Town, South Africa, and emigrated to Tennessee, United States, with his family when he was five.

Sacks is a member of the so-called "PayPal Mafia", a group of founders and early employees of PayPal who went on to found a series of other successful technology companies.

According to a 2024 New York Times article, "Over the last few years, Mr. Sacks, a longtime associate of Elon Musk and Peter Thiel, has transformed from a prominent Silicon Valley executive into an unlikely media celebrity for would-be entrepreneurs, especially those leaning right, who listen to his popular All-In podcast.

His family lives on Broadway in Pacific Heights, San Francisco, in an area known as "Billionaire's Row".[78] In June 2024, they hosted a sold-out fundraiser for Donald Trump at their home, with tickets from $50,000 to $300,000 per person. For his 40th birthday, rented a $125 million-dollar mansion and threw a Marie Antoinette-themed party, called "Let him eat cake".