The Honorverse is a military science fiction book series, its two subseries, two prequel series, and anthologies created by David Weber and published by Baen Books. They are centered on the space navy career of the principal protagonist Honor Harrington. The books have made The New York Times Best Seller list.

The series began with On Basilisk Station in 1992.

The series follows Honor Harrington, military heroine and later, influential politician, during a time of extreme interstellar change and tension. Most of the more than 20 novels and anthology collections cover events between 4000 and 4022 AD with "PD" (Post-Diaspora) dating beginning with a dispersal to the stars from the Sun ("Sol") in 2103 AD. The main series novels are set primarily in a timeline beginning 40 years after Harrington's birth on October 1, 3962 AD (1859 PD), and some short stories flesh out her earlier career. Additional novels and shorter fiction take place up to 350 years earlier, and still-earlier canon history is filled in between narratives and in appendices attached to the main novels and anthologies.

The political makeup and history of the series frequently echoes actual history, particularly that of Europe in the last half of the second millennium. The series is consciously modeled on the Horatio Hornblower series by C. S. Forester, and its main character, like Horatio Hornblower, on a mix of Thomas Cochrane and Admiral Lord Nelson. Weber originally planned for Harrington to die in the fifth book. This was later changed to parallel Nelson by having her die at the peak of her career in the climactic Battle of Manticore in 1921 PD (4024 AD), then continue the series with her children as the main protagonists. However, collaborating author Eric Flint intervened, asking for the invention of a mutual enemy for both the Star Kingdom of Manticore and the Republic of Haven to oppose in a spy-and-counterspy spin-off sub-series the two contractually agreed to co-write, just as they have contracts to write in Flint's 1632 universe. This "rethink" and redesign caused Weber to move the series' internal chronology up by about 20 years and begat the Crown of Slaves novel, first in the "Crown of Slaves" sub-series based on a number of the short stories of the first four collections. In this scenario, proxies for Manticore and Haven oppose the same hidden enemy, the genetic slavers and powers behind the government and corporations of the planet of Mesa. Mesa is later revealed in Mission of Honor to be part of a secret cabal of about a dozen highly capable planets that are busily building a secret navy using advanced technologies at a secret planet and known to itself as the Mesan Alignment. The Mesan Alignment's navy has new technology and conducts a sneak attack on Manticore in 1922 PD during the twelfth mainline novel, Mission of Honor. The Mesans have a 600-year-old secret program to reinstitute purposeful genetic engineering of humans and break up the Solarian League, while taking down all opponents opposing such genetic engineering. This makes the staunchly anti-genetic-slavery star nations of Haven, Manticore, and various associates of the planet Beowulf primary targets of the Mesan Alignment. The "Crown of Slaves" sub-series books and last two mainline Honorverse novels detail the rising extent of this threat.

As the two sub-series progress, albeit with somewhat-separate casts of characters, each is expected by Weber to carry the detailed storyline events particular to their astrographical region forward and tie together into an ongoing plotline concerning the massive and monolithic Solarian League, which foreshadowing in the most recent novels suggests is about to undergo severe disruption. The thirteenth mainline novel, A Rising Thunder, ties together events in both sub-series and synchronizes the timeline of each sub-series with Honor Harrington's mainline novels. This book confirms the Solarian League is officially now the new Mesan cat's paw, effectively at war with both the Star Empire of Manticore and the Republic of Haven, as it has been manipulated into error after error by the operatives of the Mesan Alignment.

Among a handful of anthologies, the thirteen Honor-centered novels, and two subordinate sub-series starring some different characters, the universe first explored in On Basilisk Station has a diasporal historical background for the backstory storyline, in which mankind, over almost two millennia, migrated to systems beyond the Sol system, first in slower-than-light starships, then by increasingly efficient and effective hyperspace drive-propulsion systems. Early daughter colonies also spawned colonies, forming regional networks of related populations. With travel limited to slower-than-light speeds, any marginally habitable nearby planet was of interest, and Earth's scientists went through a period in which they regularly genetically modified the human genome for survival positive adaptations to marginal environments, such as heavy gravity, thin atmosphere, thick atmospheres, or toxic environments (e.g. Grayson). Some corporate entities also began breeding for super soldiers and superior intellects, good looks, sexual prowess, etc., or mixes of such traits, practices that led to a horrific "Final War" on Old Earth. Long-established and advanced daughter colonies like Beowulf mounted a variety of rescue missions and initiated a thousand-year effort to clean up the Earth gene pool. For a time, the cultural centre moved off the Earth as it took about 500 years for the planetary economy to recover its pre-eminence within its shell of highly populated, highly developed planets. Located in the center of the spherical Solarian League, Earth's Old Chicago eventually re-emerged as the nominal League Capital.

By the Gregorian calendar currently in use, the Honorverse novels are dated beginning with year 2103 A.D.—the epoch date of the Diaspora's beginning.

The FTL hyperspace propulsion system in the stories is around 600 years old at the time period in which the novels are placed. This technology uses the ability to "sail" along a vast network of "gravity waves" on different successively higher hyperbands, each higher band giving a more-efficient speed multiplier but requiring more powerful (therefore bulkier and more expensive) engines to reach; the higher bands significantly shortening transit times on a given gravity wave for a given base speed, which is limited by particle densities and radiation shielding as Newtonian speeds increase. Analogous to prevailing trade winds creating certain favoured sea routes on Earth, the relatively static fixed gravity waves form favoured travel paths. A lack of gravity waves in some regions means that they must be plodded across by relatively slower means. These favorite routes and desert crossing points are susceptible to illegitimate exploitation by pirates and commerce-raiding warships, both interested in preying on the rich pickings of the interstellar merchant cargo ships that carry upwards of 2–7 million metric tonnes of cargo.