Claire DeMatteis is a Delaware attorney who has served as senior advisor to three Delaware Governors, served as Senior Counsel to then-U.S. Senator Joe Biden, and has made impactful contributions in all three branches of state government. She was inducted into the Delaware Women’s Hall of Fame in October 2025.

During Governor Carney’s Administration, Claire was the first woman to lead Delaware’s correctional system, which is the state’s largest law enforcement agency, with a dual mission of public safety and offender rehabilitation. Following an inmate riot and murder of a correctional officer in February 2017, she was appointed as the Governor’s special assistant to the Department of Correction (DOC), and within one year worked with the DOC team to implement more than 40 reforms to strengthen officer training, enhance inmate programming and services, modernize correctional operations, and improve reentry services. Claire served as DOC Commissioner through 2021, leading the state’s prison system through the COVID pandemic.

Governor Carney then tapped Claire to lead the coordination of more than one billion dollars in federal stimulus and COVID relief funds the state received for pandemic response and economic stabilization. From 2022-2025, Claire led Delaware’s newly-centralized Department of Human Resources, overseeing recruitment, retention, compensation, and modernization of HR services for tens of thousands of state employees.

During the Markell Administration, Claire served as Chair of the Delaware Commission for Women, responsible for advocating for women’s advancement.

After earning her law degree, Claire served as legal assistant to then-Governor Mike Castle, coordinating Delaware’s first-in-the-nation partnership to provide universal access to healthcare for the state’s children with Nemours Children’s Health System.

Claire served as Senior Counsel to then-U.S. Senator Joe Biden from 1994 to 2004, where she was instrumental implementing laws and policies that enhanced law enforcement, women’s rights, and civil rights.

From 2004 to 2016, Claire served in the private sector as partner in a large law firm, and then as senior executive, general counsel and chief compliance officer for two multi-billion-dollar corporations.

Claire is the author of the forthcoming biography of Delaware Judge Collins J. Seitz, Sr., who was the first judge in the country to desegregate a public university, high school, and elementary school in the early 1950s.

Claire serves on the UD Board of Trustees and on the Nemours Children’s Health System Board of Directors. She was born, raised, and lives in Delaware with her husband Michael Marquardt. Claire was awarded the “Order of the First State,” by Governor Carney in January 2025, which is the state’s highest civilian honor. She was inducted into the University of Delaware Alumni Wall of Fame in 2023