Jennifer Williams (born October 11, 1982) is an American United States Department of State official who has served as a special advisor to U.S. vice president Mike Pence on European and Russian affairs. Williams testified under subpoena, in the impeachment hearings of Donald J. Trump, in closed-door hearings before the House intelligence, Oversight, and Foreign Affairs committees on November 9, 2019. She gave public testimony to the House of Representatives ten days later.