Bill is a thirty-something British biologist who specializes in the cultivation and study of triffids. Because he suffers a venomous plant sting at work, he is bandaged and misses the spectacular comet that blinds the rest of the world. He starts off believing isolation is the safest route but gradually realizes the necessity of building a community. He possesses practical survival skills and a deep scientific understanding of the predatory plants threatening humanity.

Josella is a wealthy, attractive woman who survives the global blinding by sleeping through the comet. She achieved financial independence and notoriety before the crisis by writing a controversial book about female sexual empowerment. She firmly believes the sighted have a moral duty to help the blind and supports extreme, pragmatic measures to rebuild human society.

Coker is an opportunistic survivor who easily adapts his speech patterns to blend with different social classes. He strongly disagrees with the isolationist plans of other sighted groups and uses extreme methods to force sighted people to serve the blind. Despite his ruthless tactics, his actions stem from a genuine desire to help those who cannot help themselves.

Torrence is a heavily armed, redheaded survivor who establishes himself as a regional military commander. He believes in creating a feudal society where the sighted rule over the blind with absolute authority. He aggressively attempts to conscript other survivors into his brutal system.

Michael is the practical, highly organized leader of a survivor group situated at University Building. He focuses on long-term survival for humanity rather than short-term comfort or traditional morality. He pushes for a system of mandatory procreation, believing it is the only statistical way to ensure future generations will retain their sight.

Miss Durrant is the stern, highly religious leader of the Tynsham survivor group. She breaks away from the University Building faction because she finds their plans for mandatory procreation repulsive. She insists that everyone in her community adheres strictly to traditional Christian values, even if it hampers practical survival efforts.

Dr. Vorless is an older man and a prominent member of the University Building committee. He acts as the philosophical architect for the group's radical new laws. He boldly tells the survivors they must abandon their pre-comet morality and embrace communal child-rearing to repopulate the earth.

Susan is a young sighted girl who joins Bill on his journey across the country. She harbors an intense hatred for triffids after they decimate her family. She learns to defend herself quickly and takes an active, enthusiastic role in hunting the dangerous plants as she grows older.

Walter is a triffid expert who works alongside Bill. Long before the global catastrophe, he forms the controversial theory that triffids are intelligent and communicate with one another. He believes the plants would easily overtake humanity if humans ever lost the advantage of sight.

Dennis is the owner of Shirning Farm who loses his sight after the comet event. Rather than waiting passively for rescue, he constructs protective gear and braves the plant-infested roads to secure supplies for his household. He retains a strong desire for independence despite his physical limitations.

Mary is Dennis's wife and a resident of Shirning Farm. She also loses her sight to the comet and is pregnant during the apocalyptic event. She works alongside her husband to maintain their rural sanctuary and cares deeply for the others sharing their home.

Joyce is a blind resident of Shirning Farm who suffers a severe triffid sting early in the crisis. Thanks to Dennis and Mary's intervention, she survives the venom but remains dangerously ill for an extended period while the world collapses outside.

Tommy is Susan's four-year-old brother. He encounters a triffid in the family's front yard, prompting his sister to seek immediate help from strangers passing through the town.

Stephen is a former Stock Exchange member who bunkers down at Charcott Old House with his companions. He actively collects flamethrowers and heavy weaponry to fortify their heavily defended manor against the roaming plants.

Ivan is a survivor from the University Building group who serves as their primary aviator. He scouts the countryside from the air, tracking survivor movements and searching for suitable locations to rebuild civilization.

Elspeth is a reporter who joins the University Building survivor group. She immediately recognizes Josella from her controversial publishing history and works to document the strange new society forming on the campus.

Sandra serves as the "professional remembrancer" for Beadley's group. She is tasked with preserving records and maintaining institutional memory as the survivors attempt to lay the groundwork for a new civilization.

Umberto is a notorious pilot who claims to have sourced superior triffid oil from a secretive location. His mid-flight explosion scatters seeds globally, leading to the worldwide proliferation of the walking plants long before the comet arrives.

Alf is a rough-mannered blind man who aligns with Coker. He helps enforce Coker's will by guarding the captive sighted individuals and ensuring they follow orders regarding the care of the blind.

The Colonel is a traditional, no-nonsense military figure. He assists Beadley in organizing the early survivor community and stresses duty, discipline, and order in the face of the global disaster.