Dann Thomas' earliest comic book credit appears on "The Sea of No Return" (credited as "Adapted from a story by Danette Couto") in Savage Sword of Conan #66 (July 1981). Her husband credits her with the original idea for Arak, Son of Thunder, noting, "Danette Couto (soon to be Dann Thomas) had this idea: What if a Native American had discovered Europe?" She began co-writing the Arak title with issue #12 (Aug. 1982) and would work with Thomas on most of his projects afterward. Dann Thomas co-wrote Wonder Woman #300 (Feb. 1983) and, as Roy Thomas noted in 1999 "became the first woman ever to receive scripting credit on the world's foremost super-heroine." Dann Thomas' last new comic book writing appeared in Cadillacs and Dinosaurs #9 (Nov. 1994), published by Topps Comics.

The superheroine Firebrand of the All-Star Squadron takes her civilian name, Danette Reilly, from Dann Thomas. Dann Thomas co-wrote later issues of All-Star Squadron, subsequent to the introduction of Firebrand.Another character based upon Dann Thomas is a woman named Danette who appeared in the story "What If Conan the Barbarian Walked the Earth Today?" published in What If? #13 (Feb. 1979).

DC Comics

• Action Comics Weekly #623-626
• All-Star Squadron #46, 51-55, 58-59, Annual #3
• America vs. the Justice Society #1-4
• Arak, Son of Thunder #12-50, Annual #1
• Best of DC #69
• Captain Carrot and His Amazing Zoo Crew! #16
• Crimson Avenger #1-4
• Infinity Inc. #1-53, Annual #1-2, Special #1
• Jonni Thunder a.k.a Thunderbolt #1-4
• Last Days of the Justice Society Special #1
• The New Teen Titans #38
• Secret Origins #5 (Crimson Avenger), #26 (Miss America)
• Shazam! The New Beginning #1-4
• Wonder Woman #300
• Young All-Stars #1-31, Annual #1

Marvel Comics

• Avengers Annual #19-20
• Avengers Spotlight #37-39
• Avengers West Coast #60-63, 65-94, 96, Annual #5-7
• Black Knight #1-4
• Doctor Strange, Sorcerer Supreme #5-24, 26-40
• The Herod Factor #1
• Impossible Man Special #1
• Iron Man Annual #11-12
• Marvel Super-Heroes #6-7
• Nightmask #6-7, 10-12
• Saga of the Sub-Mariner #1-12
• Savage Sword of Conan #66 (credited as "Danette Couto"), #190-195, 207-210, 225
• Spider-Woman #1-3
• Thor Annual #15

Other publishers

• Alter Ego #1-4 (First Comics) (not to be confused with Alter Ego )
• Cadillacs and Dinosaurs #9 (Topps Comics)
• Cormac Mac Art #1-4 (Dark Horse Comics)
• Crime Smasher Special Edition #1 (Blue Comet Press)
• Captain Thunder and Blue Bolt (Vol. 1) #1-10 (Hero Comics)
• Captain Thunder and Blue Bolt (Vol. 2) #1 (Hero Comics)
• Wally Wood's T.H.U.N.D.E.R. Agents #1-2, 4 (Deluxe Comics)
• Within Our Reach #1 (Star*Reach)