On August 30, 2014, Wagner married former White House nutrition policy advisor and assistant chef Sam Kass in a ceremony held at Blue Hill at Stone Barns, a restaurant in Pocantico Hills, New York.[21] The wedding was attended by then U.S. President Barack Obama and his family, as Kass is a family friend of the former president.[21][22] In 2017, Wagner gave birth to their son, Cy.[23]