David L. Cohen (born 1955) is an American businessman, attorney and lobbyist who has served as the United States ambassador to Canada since December 2021. He previously served as the senior advisor to the CEO of Comcast Corporation. Until January 1, 2020, he was senior executive vice president and chief lobbyist for Comcast. He also served as chairman of the board of trustees for the University of Pennsylvania and was chief of staff to former Philadelphia Mayor Ed Rendell.