Bradley is best known for The Mists of Avalon (1983), a landmark retelling of the Arthurian legend from the perspectives of its female characters—Morgaine, Viviane, and Gwenhwyfar. The novel became an international bestseller and is widely regarded as a classic of feminist fantasy. She later co-authored Avalon sequels with Diana L. Paxson, expanding the saga.
Among her other major works is The Firebrand (1987), which reimagines the Trojan War through the eyes of Kassandra. She is also celebrated for the Darkover series, a sprawling science fantasy saga set on a lost human colony world, which began in 1958 and grew to include more than twenty novels, many co-written with other authors.
In addition, Bradley edited the long-running Sword and Sorceress anthology series, which championed women writers in heroic fantasy. Her work remains influential in the fantasy genre, particularly for its focus on female perspectives.