Arthur William Kopp (February 28, 1874 - June 2, 1967) was a U.S. Representative from Wisconsin.
Born in Bigpatch, Wisconsin, Kopp attended the common schools of Grant County, Wisconsin. He was graduated from the State normal school, now the University of Wisconsin–Platteville in Platteville, Wisconsin, in 1895. He taught school for three years. He was graduated from the law department of the University of Wisconsin–Madison in 1900, and was admitted to the bar the same year and commenced practice in Platteville, Grant County. He served as member of the board of aldermen in Platteville 1903-1904, and was the city attorney in 1903 and 1904. He served as district attorney of Grant County 1904-1908.
Kopp was elected as a Republican to the Sixty-first and Sixty-second Congresses (March 4, 1909-March 3, 1913). He was not a candidate for reelection to the Sixty-third Congress. He resumed the practice of law.
Kopp was elected circuit judge of the fifth judicial district of Wisconsin in 1942 and served until his retirement January 1, 1955. Arthur Kopp was a reserve circuit judge after retirement, accepting occasional assignments. He was also a law consultant. He died in Platteville, Wisconsin, on June 2, 1967. He was interred in Greenwood Cemetery.