Charles Sheffield, was an English-born mathematician, physicist and science-fiction writer who served as a President of the Science Fiction and Fantasy Writers of America and of the American Astronautical Society.

The Science Fiction and Fantasy Writers of America, doing business as Science Fiction and Fantasy Writers Association, commonly known as SFWA is a nonprofit 501(c)(3) organization of professional science fiction and fantasy writers. While SFWA is based in the United States, its membership is open to writers worldwide. The organization was founded in 1965 by Damon Knight under the name Science Fiction Writers of America. The president of SFWA as of July 1, 2021 is Jeffe Kennedy.