Newhouse gave money to charity, including $15 million to Syracuse University. He was also an art collector, who at one time owned one of the most valuable paintings in the world, a Jackson Pollock drip painting, titled No. 5, 1948. Newhouse was listed by Art News as among the top 200 art Collectors in the world.
He was married to Jane Franke from 1951–59, and they had three children, Sam, Wynn (died 2010), and Pamela. In 1973, he married Victoria Carrington Benedict de Ramel, who survived him.
