Azariah Smith Root (February 3, 1862 – October 2, 1927) was an American librarian and educator. Root earned both bachelor's and master's degrees from Oberlin College in 1884 and 1887 respectively. He went on to study law at Boston University from 1884 to 1885 and at Harvard University from 1886 to 1887. Later, Root studied library science and bibliography at the University of Göttingen from 1888 to 1889. Root returned to Oberlin College in 1890 as the library director and a professor of bibliography, positions he would hold until his death.