How you cite an author whose last name is represented by an initial depends on what kind of name it is. Authors whose last names are represented by initials generally appear in one of two categories. The first category includes authors whose names are stage names or pseudonyms. Consider as an example the songwriter Karen O. Her real name is Karen Orzolek, but her stage name is intended to be understood as a unit, not as a first name and an initial. So it is unnecessary to treat her stage name as a conventional first name and last name or to give her real name in a works-cited-list entry. The following provides an example of such an entry:

Karen O. “Rapt.” Crush Songs, Cult Records, 2014.

The second category includes authors whose names appear either partially or wholly as initials in publications. For an author in this category, it is best to supply the full or conventional name in your works-cited list. The nineteenth-century writer A. S. Moffat is an example of this kind of author. It was common in the nineteenth century for female authors to be identified by their initials only, so Moffat was often referred to as “A. S. M.” on the title pages of her books. If you are writing a historical analysis of her books, readers would find it useful to know the author’s full name, which can be supplied in brackets to supplement the initials that appear on the title page. The following provides an example of an entry for a book by Moffat:

M[offat], A. S. Cedar Brook Stories; or, The Clifford Children. Graves and Young, 1863. 

You should try to weigh the intentions of authors or publishers when you are deciding how to present their names. Karen O. chose to present her name in a certain way. However, the presentation of A. S. Moffat’s name as A. S. M. does not convey anything essential about the author; in fact, it obscures her identity.

See also our related post about citing authors known only by initials.