William Ross Cotter (born July 18, 1926) was a Democratic member of the United States House of Representatives from Connecticut. He represented Connecticut’s 1st Congressional District and served as a federal legislator during the latter part of the 20th century. Identified in congressional records under the bioguide ID C000799, Cotter was one of the state’s prominent Democratic voices in the U.S. Congress.

Cotter began his congressional service on January 21, 1971, and remained in office until January 3, 1983. Over the course of these twelve years, he served six terms in the House of Representatives, consistently representing Connecticut’s 1st District. During this period he held the formal role of Representative, and his tenure marked him as a historical member of Congress from Connecticut. After leaving office, he was regarded as a former member of the House, with his service spanning a significant portion of the early 1970s through the early 1980s.