Holder is six-time winner of the Bram Stoker Award, received a Scribe Award from the International Association of Media Tie-In Writers for Best Novel, and was named a Grand Master by that organization in 2019. She also received a Young Adult Literature Pioneer Award from RT Booksellers.
Holder has written many licensed novels set in universes such as Teen Wolf, Buffy the Vampire Slayer, Angel, Saving Grace, Hellboy, Smallville, Wishbone, Kolchak the Night Stalker, The Green Hornet, Domino Lady, and Zorro. She also novelized the movies Ghostbusters, Wonder Woman, and Crimson Peak. She sold approximately two hundred short stories as well as essays on writing, popular culture, and horror.
Holder coauthored the New York Times bestselling Wicked series and the teen thriller The Rules. She is the author of the young adult horror series Possessions. She also co-edited Sherlock Holmes of Baking Street and has written pastiches, articles, and essays about Holmes for various journals and books.
- Halloween Rain (with Christopher Golden)
- The Angel Chronicles, Volume 1
- Blooded (with Golden)
- Child of the Hunt (with Golden)
- The Gatekeeper Trilogy
- The Angel Chronicles, Volume 3
- Sunnydale High Yearbook (with Golden)
- Immortal (with Golden)
- City Of
- The Angel Chronicles, Volume 2
- Not Forgotten
- The Evil That Men Do
- The Book of Fours
- The Journals of Rupert Giles
- Endangered Species
- Blood and Fog
- Chosen: The One
- Stake Your Destiny
- Queen of the Slayers
- Carnival of Souls
- Demons of the Hellmouth
- "Absalom Rising"
- "Have Gunn, Will Travel"
- Tales of the Slayer
- The Watcher's Guide, Volume 1
- The Watcher's Guide, Volume 2
- The Casefiles, Volume 1 (with Mariotte and Maryelizabeth Hart)
- Seven Seasons of Buffy
- Five Seasons of Angel
- The Making of a Slayer
- Buffy the Vampire Slayer Encyclopedia (with Lisa Clancy)