David Duvall Orr (born October 4, 1944) is an American Democratic politician from Chicago, Illinois. He was Alderman of the 49th Ward in Chicago from 1979 to 1991. In 1987, he served briefly as Mayor of Chicago after the death of Mayor Harold Washington. Since 1991, he has been County Clerk of Cook County. As County Clerk, he is responsible for the third largest election district in the United States (among other duties). Orr is a graduate of Simpson College in Indianola, Iowa.