Otis Adelbert Kline was an American literary agent and author best known for his contributions to the pulp fiction genre, particularly in the early 20th century. Kline is often associated with the "sword and planet" subgenre, which combines elements of adventure, science fiction, and fantasy.
His most famous work is The Swordsman of Mars (1933). Kline is also known for his novelistic feud with Edgar Rice Burroughs.
Otis Adelbert Kline was born in Chicago. He was an amateur orientalist and a student of Arabic, like his friend and sometime collaborator, E. Hoffmann Price. Kline has been an associate editor of Weird Tales magazine since its inception.
Otis Adelbert Kline debuted with Planet of Peril (1929). He wrote two other novels set on the planet Venus, which are written in the storytelling form of the John Carter of Mars novels, prompting Burroughs to write his own stories set on Venus.
In return, Kline wrote two novels set on Mars, as well as several jungle adventurers quite reminiscent of Burroughs's Tarzan.
In the mid-1930s, Kline largely abandoned writing to concentrate on his career as a literary agent (most famously for fellow Weird Tales author Robert E. Howard, pioneer sword and sorcery writer and creator of Conan the Barbarian).
Kline represented Howard from the Spring of 1933 until Howard's death in June 1936 and continued to act as a literary agent for Howard's estate thereafter.