Joseph Adna Hill (1860-1938) was an American statistician, born in Stewartstown, New Hampshire, he graduated from Harvard University in 1885 and received a Ph.D. from the University of Halle in 1892. He published The English Income Tax with Special Reference to Administration and Method of Assessment in 1899.

In 1898 he began work as a statistician for the U.S. Census Bureau and became chief statistician in 1909. As chief statistician, he oversaw publication of reports on child labor, illiteracy, marriage and divorce, women at work, and a report for the Immigration Commission on occupations of immigrants. He was appointed assistant director of the Census Bureau in 1921.

Although revised by Edward Vermilye Huntington, Hill is credited with the conception of the Method of Equal Proportions or Huntington-Hill method for apportioning seats in the U.S. House of Representatives to the states, as a function of their populations determined in the United States census. This mathematical algorithm has been used in the United States since 1941 and is currently the method used.