Sesyle Joslin is a children's literature author. Joslin's book What Do You Say, Dear? was illustrated by Maurice Sendak and it was a Caldecott Medal Honor book in 1959.

Seth W. Godin is an American author and former dot com business executive.

Seth Grahame-Smith is an American writer and film producer, best known as the author of The New York Times best-selling novels Pride and Prejudice and Zombies and Abraham Lincoln, Vampire Hunter, both of which have been adapted as feature films. Grahame-Smith is also the co-creator, head writer and executive producer of The Hard Times of RJ Berger, a scripted television comedy appearing on MTV. In collaboration with David Katzenberg, his partner in Katzsmith Productions, Grahame-Smith is currently developing a number of projects for television and film.

Seth Lloyd is a professor of mechanical engineering and physics at the Massachusetts Institute of Technology.

Sethus Calvisius or Setho Calvisio, originally Seth Kalwitz, was a German music theorist, composer, chronologer, astronomer, and teacher of the late Renaissance.

Seton Ingersoll Miller was an American screenwriter and producer. During his career, he worked with film directors such as Howard Hawks and Michael Curtiz. Miller received two Oscar nominations and won once for Best Screenplay for fantasy romantic comedy film Here Comes Mr. Jordan (1941) along with Sidney Buchman.

Seva Novgorodsev MBE is a former radio presenter on the BBC Russian Service, and is famous through the former Soviet Union.

Sever Feliksovich Gansovsky was a Soviet science fiction author. He mostly wrote short stories.

Severian, Bishop of Gabala in Syria, was a popular preacher in Constantinople from around 398/399 until 404. He became the enemy of John Chrysostom and helped condemn him at the Synod of the Oak.

Severo Sarduy was a Cuban poet, author, playwright, and critic of Cuban literature and art. Some of his works deal explicitly with male homosexuality and transvestism.