Mary Emogene Hazeltine (May 5, 1868 – June 17, 1949) was an American librarian.

[1] She graduated from Wellesley College, Massachusetts with her bachelor's degree in 1891 and served as the librarian for the James Prendergast Library in Jamestown, New York from 1893 to 1906.

[1] During that time she also organized and directed the Chautauqua School for Librarians in the summers from 1901 to 1905.

Hazeltine retired from the Library School at Madison in 1938 and returned to her family home in Jamestown, New York.

Hazeltine was inducted into the Wisconsin Library Hall of Fame in 2008.