Willett S. Main (August 15, 1828 – July 5, 1902) was an American politician.
Born in Edmeston, New York,[1] Main moved with his family to Clarksville, New York,[1] then to Waukesha County, Wisconsin Territory in 1846, and then to Madison, Wisconsin Territory in 1847. He was a farmer and merchant. He served as sheriff and under-sheriff of Dane County, Wisconsin and was a deputy United States Marshal. He served in the Wisconsin State Senate, as a Republican, from 1888 to 1892.[2] He died of heart disease near Madison, Wisconsin.[1][3] His brother was Alexander H. Main, who served in the New York State Assembly,[4] and he was the brother-in-law of Senator John Coit Spooner.[1]