Red Sonja is a fictional character, a sword-and-sorcery comic-book heroine created by writer Roy Thomas and artist Barry Windsor Smith for Marvel Comics in 1973, partially based on Robert E. Howard's own creation 'Red Sonya of Rogatino' a female swashbuckler from his 1934 short story The Shadow of the Vulture and to a certain degree also based on Howard's character Dark Agnes de Chastillon.
Red Sonja debuted in Conan the Barbarian #23 (cover-dated Feb. 1973). Roy Thomas created a new origin story and transposed the timeline from the 16th century of Howard's original Red Sonya, to the Hyborian Age, another Howard creation, in order to have the comic-book Red Sonja interact with Conan the Barbarian. In 1975 Marvel Comics published the first issue of Red Sonja after the character headlined Marvel Feature for seven issues that same year.
At the 2013 Emerald City Comic Con, Dynamite, which began publishing Red Sonja comics in 2005, announced that Gail Simone would be writing a new ongoing Red Sonja series. Simone noted in further interviews that her version is slightly rebooted, showing the character's beginnings. Issue #1 of Simone's run was released in July 2013, and reviews were positive. The series ran through 18 issues. In 2017, a new Red Sonja comic series began, written by Amy Chu.
She was portrayed by Brigitte Nielsen in the 1985 film Red Sonja. In 2011, Sonja was ranked first in Comics Buyer's Guide's 100 Sexiest Women in Comics list.