"Jack knew how to communicate as few others do and did it with eloquence, wit, and grace. He made an invaluable contribution to ABC News and we mourn his loss," said David Weston, ABC news president, in a statement Thursday.
Smith, an award-winning journalist who began reporting for ABC News in 1976, was the network's Washington, D.C., correspondent until he left ABC News in 2001.
He was a frequent contributor to "This Week with David Brinkley" and "Good Morning America."
Most recently, Smith created the "Cutting Edge" segments on "World News Tonight with Peter Jennings," making him the only network journalist to cover the digital world on a regular basis.
Smith, the son of TV news veteran and former ABC News anchor Howard K. Smith, is survived by his wife, Pam; son, Alexander, and mother, Benedicte Traberg Smith.
Funeral arrangements are incomplete at this time.
Susan Sarandon 'very excited' about daughter's pregnancy
Senate Democrats to pull all-nighter on climate change