John Walker — eldest of the Walker children and Captain of the Swallow
Susan Walker — Mate of the Swallow and the cook and domestic organizer
Titty Walker — Able Seaman and the most imaginative of the Walkers
Roger Walker — originally Ship's Boy, later Able Seaman, mischievous, mechanical and very fond of chocolate. He is the youngest of the children apart from the baby.
Bridget Walker — Ship's Baby who proves to be a brave member of the crew in Secret Water. Referred to as Vicky in Swallows and Amazons because of her supposed resemblance to Queen Victoria.
The Amazons
Nancy Blackett (real name: Ruth) — Captain of the Amazon; an enterprising leader. She is an imaginative and lively girl who is always willing to create fantasies and adventures.
Peggy Blackett (real name: Margaret) — Mate of the Amazon, Nancy's sister; although a bit timid, tries to live up to Nancy's expectations
The Ds
Dorothea Callum — imaginative romantic novelist introduced in Winter Holiday with her younger brother.
Dick Callum — Dorothea's younger brother who is scientific and thoughtful, usually comes up with solutions to technical problems. Though younger than his sister, Dick is Captain of the Scarab and she the First Mate.