Donald Leroy Bonker (born March 7, 1937 in Denver, Colorado) is an American former congressman for the state of Washington and a Democrat. He served as a member of the United States House of Representatives from 1975 to 1989, representing Washington's third Congressional district. He is a resident of Bainbridge Island, Washington. He served as aide to United States Senator Maurine Brown Neuberger from 1964 to 1965, Clark County auditor in Vancouver from 1966 to 1974, and as a delegate to Washington State Democratic conventions from 1968 to 1970.