The Ologies are a series of illustrated, interactive, montessori style books presented in an encyclopedic format. The inspirations for the topics range from fantasy (myths, creatures, paranormal) to non-fictional human and natural history. The series is primarily authored and edited by Dugald Steer. The authors on many of the books are pseudonyms. However, some of the pseudonyms used such as Dr Ernest Drake from the Dragonology portion of the series may have been based off living people. The books are published by Templar Publishing in the United Kingdom, Five Mile Press in Australia, Rizzoli Libri in Italy and Candlewick Press in the United States. The first book, Dragonology: The Complete Book of Dragons (2003), remained on the New York Times' children's bestsellers list for 76 weeks.^[1]

The books, which are intended for young readers, have spawned additional merchandise including action figures, plush toys, board games and card games, and a video game.

Each of the books is given a fictional "author", and purport to be lost journals of fictional investigators. Since the books follow an encyclopedia format rather than a narrative, Steer has said that "it's slightly different from traditional reading. Readers can dip in and out, but the essential story is told in a linear way."^[2]

The large-format books contain many novelty items of ephemera including removable maps and postcards, letters that can be unfolded, and tactile items such as “dragon scales”, "mummy cloth" and "gold doubloons".

The books are illustrated by a variety of artists, including Helen Ward, Wayne Anderson, Nghiem Ta, Chris Forsey, A. J. Wood, Douglas Carrel, J.P. Lambert, Ian P. Andrew, Nick Harris, Anne Yvonne Gilbert, John Howe, Tomislav Tomic, G. Hunt, R. Sella, and Carole Thomann.

• Dragonology: The Complete Book of Dragons By Dugald A. Steer (2003)
  • The Dragonology Handbook: A Practical Course in Dragons by fictional character Doctor Ernest Drake
  • A Dragonology Code Writing Kit
  • Dragonology The Coloring Book
  • Dragonology The Colouring Companion
  • Working with Dragons: A Course in Dragonology
  • Drake's Comprehensive Compendium of Dragonology
  • Tracking and Taming Dragons Volume 1: European Dragon By Dugald A. Steer, Ernest Drake
  • Tracking and Taming Dragons Volume 2: Frost Dragon By Dugald A. Steer
  • Dragonology Field Guide to Dragons
  • Bringing Up Baby Dragons: A Guide for Beginners
  • Obscure Spells and Charms of Dragon Origin: A Dragonology Kit
  • Dragonology Pocket Adventures:
    1. The Iceland Wyrm
    2. The Dragon Star
    3. The Dragon Dance
    4. The Winged Serpent
  • Dragonology Chronicles:
    1. The Dragon’s Eye
    2. The Dragon Diary
    3. The Dragon’s Apprentice
    4. The Dragon Prophecy
• Egyptology: Search for the Tomb of Osiris (2004)
  • The Egyptology Handbook: A Course in the Wonders of Egypt
  • An Egyptologist's Writing Kit
  • Wonders of Egypt: A Course in Egyptology
  • Egyptology the Coloring Book
• Wizardology: The Book of the Secrets of Merlin (2005)
  • The Wizardology Handbook: A Course for Apprentices
  • A Wizard's Code Writing Kit
  • A Guide to Wizards of the World
• Pirateology: A Pirate Hunter's Companion (2006)
  • The Pirateology Handbook: A Course in Pirate Hunting
  • A Pirateology Code Writing Kit
  • Pirateology Handbook: A Course for Seafarers
  • Pirateology Handbook: A Cabin Boy’s Course in Pirate Hunting
  • A Pirate's Guidebook and Model Ship Set
  • Pirateology Guide to Life on Board a Pirate Ship
• Mythology: Greek Gods, Heroes, & Monsters (2007)
  • The Mythology Handbook
• Monsterology: The Complete Book of Fabulous Beasts (2008)
  • The Monsterology Handbook: A Practical Course in Monsters
  • Working with Monsters: A Course in Monsterology
• Spyology: The Complete Book of Spycraft (2008)
• Eragon's Guide To Alagaesia By Christopher Paolini (2009)
• Oceanology: The True Account of the Voyage of the Nautilus by Dugald Steer and Emily Hawkins (2009)
  • The Oceanology Handbook: A Course for Underwater Explorers
• Vampireology: The True History of the Fallen Ones (2010)
• Alienology: The Complete Book of Extraterrestrials (2010)
• Illusionology: The Secret Science of Magic (2012)
• Dinosaurology: The Search for a Lost World (2013)
• Dungeonology - made in collaboration with Dungeons & Dragons (2016)
• Knightology: A True Account of the Most Valiant Knights (2017)
• Ghostology: A True Revelation of Spirits, Ghouls, and Hauntings by fictional "Ghostologist" Lucinda Curtle and Dugald Steer (2020)
• Dr. Ernest Drake's Collector's Library (contains two books: Dragonology and Monsterology)
• The Ology Collection (contains four books: Dragonology, Egyptology, Wizardology and Pirateology)

For some books, there were minor differences in titles and cover designs between the Italian, British, Australian and North American publishers.

In 2008, Universal Studios acquired the film rights to the Dragonology series, with Leonard Hartman set to write and executive produce the adaptation.^[5] In August 2012, it was reported that Alex Kurtzman and Roberto Orci would produce the film for Universal.^[6]

In October 2012, it was reported that Carlos Saldanha, the director of the Ice Age and Rio films, was developing for 20th Century Fox and Blue Sky Studios an animated feature film based on Alienology: The Complete Book of Extraterrestrials.^[7]

On January 31, 2018, Paramount Pictures announced they were in the process of developing a film franchise centered around all of the Ologies books (15 books as of 2024), by setting up a writers' room currently consisting of Jeff Pinkner, Michael Chabon, Lindsey Beer, Joe Robert Cole, Nicole Perlman and Christina Hodson. The vision for the franchise is the hope that each of the writers will embrace the books by working with visual artists to create treatments that will eventually evolve into seven movie scripts with interconnected stories. Paramount also announced that Akiva Goldsman is to act as overseer and producer of the franchise.^[8]