She is the love interest and later the wife of John Carter, an Earthman mystically transported to Mars, and subsequently the mother of their son Carthoris and daughter Tara.

As Burroughs describes Dejah Thoris: And the sight which met my eyes was that of a slender, girlish figure, similar in every detail to the earthly women of my past life...

Her face was oval and beautiful in the extreme, her every feature was finely chiseled and exquisite, her eyes large and lustrous and her head surmounted by a mass of coal black, waving hair, caught loosely into a strange yet becoming coiffure.

Her skin was of a light reddish copper color, against which the crimson glow of her cheeks and the ruby of her beautifully molded lips shone with a strangely enhancing effect.

Set 400 years before A Princess of Mars, the first story arc portrays Dejah's role in the rise to power of the Kingdom of Helium, as well as her first suitor.

In Pierce Brown's book Morning Star, Dejah Thoris is the name of a dreadnought battleship, which belongs to a character nicknamed Mustang.

In the story "Mars: The Home Front" by George Alec Effinger, Dejah Thoris is kidnapped by the sarmaks and taken to their space gun base.

In the earlier prequel short story "Allan and the Sundered Veil" by Alan Moore, a 'time lost' Carter sees a vision of himself fighting a Green Martian and winning Dejah Thoris in a "chrono-crystal aleph" (from Jorge Luis Borges's "The Aleph") In The Apocalypse Troll by David Weber, Richard Aston refers to the very human-looking female he has rescued from a sinking UFO as Dejah Thoris.

In Battle Angel Alita: Mars Chronicle, volume 7, page 37,[6][7][8] one of the spaceships is name Dejah Thoris, in direct reference to the novels.