The chronicles revolve around Lemuel Gulliver, a pragmatic English surgeon turned voyager who embarks on oceanic journeys after his professional downfall. Gulliver, with a dry, objective narrative voice seldom revealing any profound emotional insight or introspection, describes the extraordinary encounters on his travels.

His first adventure in the miniature kingdom of Lilliput unfolds when diminutive captors discover him post-shipwreck. They are simultaneously awed and threatened by him, using force fearlessly despite their miniature weaponry. Despite this, they are largely warm-hearted, extending their hospitality even at the risk of their own resources. Gulliver's size and strength are eventually exploited in the Lilliputians' conflict against their rivals, the Blefuscudians. However, charges of treason are raised against him when he extinguishes a palace fire using his own urine. Gulliver then escapes to Blefuscu, repairs a boat, and sails back to England.

Upon his brief return home, Gulliver soon embarks on another sea exploration, landing him in the land of the colossal beings of Brobdingnag. Initially treated like an exotic pet, he is eventually sold to the queen and becomes a court entertainer. Despite his comfort, Gulliver finds himself disgusted by the magnified physical imperfections of the giant Brobdingnagians. His encounters with the gigantic fauna are perilous, and their trails on his food make consumption a challenge. His journey in Brobdingnag concludes when an eagle seizes his cage and drops it into the sea. Subsequent travels take him to the floating island of Laputa and its oppressed underlying region Balnibarbi, inhabited by frivolous scholars and academics. After a detour to Glubbdubdrib, where he conjures historical figures, and the land of the senile immortals, the Struldbrugs, he sails to Japan and eventually back to England.

In his final voyage, Gulliver lands in an unknown territory inhabited by the rational, horse-like Houyhnhnms and the brutish, humanoid Yahoos. Despite his desire to dwell with the civilized horses, his humanoid physique leads to his banishment. Stranded on a nearby island, he is rescued by a Portuguese ship captain. However, Gulliver now perceives all humans, including the captain, in the degrading light of the Yahoos. His narrative concludes with a dubious claim of England's colonial proprietorship over the lands he's traversed.