Walter Jeremiah Maddock (September 13, 1880 – January 25, 1951) was an American politician in North Dakota, US. He served in the North Dakota House of Representatives from 1915 to 1923, and became the 14th Lieutenant Governor of North Dakota in 1925. Me became the 15th Governor of North Dakota in 1928 when Arthur G. Sorlie died in office. He was the first governor born in what would eventually become North Dakota.