Charles Alexander Nelson (April 14, 1839 - January 13, 1933)[1] was an american librarian and bibliographer.

In 1864/5 he was a civil engineer in government service at New Berne, North Carolina.

From 1874 until 1881, he was connected with the book trade in Boston, and was employed in literary, library, and editorial work.

For six years, he was the Boston correspondent of the American Bookseller, and from 1876 he was on the editorial staff of Zion's Herald.

From 1891 to 1893 he worked on a catalog for the Newberry Library in Chicago, and until 1909 he was deputy librarian of Columbia University.