Dragonriders of Pern is a science fantasy series written primarily by American-Irish author Anne McCaffrey, who initiated it in 1967. Beginning in 2003, her middle child Todd McCaffrey has written Pern novels, both solo and jointly with Anne. The series (as of 2024) comprises 24 novels and two collections of short stories. The two novellas included in the first novel, Dragonflight, made McCaffrey the first woman to win a Hugo Award for writing fiction as well as the first to win a Nebula Award.

Humans have colonized the planet Pern in the Rukbat star system, but have lost much of their technology and history (including their origin on Earth) due to periodic onslaughts of Thread, a mycorrhizoid spore that voraciously consumes all organic material, including humans and their crops, given the opportunity. Thread comes from the Red Star, actually another planet. The Red Star has a 250-Turn (Pernese year) elliptic orbit around Rukbat, and when its orbit brings it close enough, Thread rains down on Pern at predictable intervals over about 50 Turns.

The Pernese use intelligent firebreathing dragons to fight Thread. A human rider has a telepathic bond with their dragon, formed by Impression at the dragon's hatching. The bonding instantly creates a very close, lifelong relationship – the dragon almost invariably commits suicide at the rider's death, and a rider whose dragon has died bears a deep emotional wound which can never be fully healed. Later books deal with the initial colonization of Pern and the genetic modification of small native animals into creatures capable of carrying humans in flight.

The Pernese live in a pre-industrial society, with lords, holds, harpers (musicians, entertainers, and teachers), and dragons, with occasional examples of higher technology (like flamethrowers, the telegraph, chemical fertilizers, and powerful microscopes and telescopes). There are four basic social classes: Weyrfolk (centered on Dragonriders) who live in Weyrs, Holders who rule Holds (cities, towns and farms), Crafters, and the Holdless who have no permanent home (including traders, displaced Holders, and brigands). The society resembles feudal Europe, but with some significant differences – especially, farmers are organized in their own guild, independent of the Holders – rather than being serfs as in historical feudal societies. Also, there is no formal religion and nothing like the Medieval Church, the closest equivalent being in fact the Dragonriders, who have a planet-wide organization and to whom a tithe is due – though they are in no way sworn to celibacy (rather the reverse).

The series as a whole covers over two and a half millennia.^{[citation needed]}

There are 24 Dragonriders of Pern novels and two story collections, the latest published in 2018. Anne McCaffrey once requested reading the works in the order they were written. That differs greatly from Pern historical order, for several reasons. The McCaffreys have published stories set in several different periods of Pern's history from initial exploration to more than 2,500 years after landing (AL). Multiple stories feature the same events from different viewpoints. Some stories feature travel between times, even across centuries. Todd McCaffrey, writing alone or with his mother after 2002, has specialized in an early time period.

These stories take place immediately before and during the Ninth Pass, about 2,500 years after landing (AL):

The trilogy was released 1978 in an omnibus edition titled The Dragonriders of Pern by Nelson Doubleday Science Fiction Book Club.