See also Recurring characters in the Aubrey–Maturin series
- Jack Aubrey: Captain of HMS Diane , post-ship Nutmeg andHM Hired Vessel Surprise .
- Stephen Maturin: ship's surgeon, natural philosopher, friend to Jack and an intelligence officer.
- Sophia Williams: Jack's wife and mother of their three children.
- Diana Villiers: Cousin to Sophia, wife of Maturin, and mother of their newborn daughter.
- Mr David Edwards: Secretary to the deceased Envoy Mr Fox. Edwards is carrying the treaty between Britain and the Sultan of Pulo Prabang.
- Mr Welby: Captain of the Marines.
- Mr Fielding: First Lieutenant on the Diane and also in the Nutmeg . He stays with the Nutmeg when she meets Surprise .
- Mr Dick Richardson: Second Lieutenant in the Diane , after Elliot is presumed dead in the pinnace. He was called Spotted Dick as midshipman when introduced in The Mauritius Command aboard HMS Boadicea .
- Preserved Killick: Captain's steward on Nutmeg and every ship that Aubrey sails.
- Barret Bonden: Coxswain to Aubrey.
- Mr Reade: midshipman on Diane , Nutmeg and Surprise , who loses his arm in the battle with the Dyaks.
- Mr Hadley: Carpenter on HMS Diane , killed in the attack by the Dyaks.
- Shao Yen: Banker on Java with whom Maturin dealt for the mission to Pulo Batang.
- Kesegaran: Seafaring Dyak woman who returned to attack the stranded Dianes.
- "Green Headcloth": Dyak chieftain.
- Li Po: Chinese junk owner and captain, who rescued the Dianes after the typhoon.
- Wan Da: Powerful Malay pirate.
Batavia and the Nutmeg of Consolation
- Sir Stamford Raffles: Lieutenant-Governor of Java with an interest in botany. He receives the treaty carried by David Edwards, from Maturin.
- Ahmed: Maturin's Malay servant, discharged amicably at Java.
- Mr Macmillan: Surgeon's mate on HMS Diane , moves to Nutmeg .
- Mr Sowerby: Cambridge-educated naturalist who seeks a government position under Raffles, in his conservatory, and who names a plant after Maturin.
- Mr Miller: One of two young gentlemen engaged in Batavia as "able", soon promoted to midshipman on Nutmeg . He is killed in the battle with Cornélie .
- Mr Oakes: The other of two young gentlemen engaged in Batavia as "able" and promoted to midshipman on Nutmeg and moved to Surprise .
- Mr Conway: Promoted from the foretop to midshipman.
- Mr David Adams: Once a skilled captain's clerk of HMS Lively ( Post Captain ), he joins the Nutmeg at Batavia, to sort the records saved from the Diane from the scientific record of water temperature.
- William Grimshaw: New mate to Killick, formerly of HMS Thunderer .
Chasing Cornélie and meeting Surprise
- Jean-Pierre (Pierrot) Dumesnil: Second Lieutenant on Cornélie ; nephew of Captain Christy-Pallière, prisoner of war after his ship was taken and the captain and first lieutenant are killed in the battle. Aubrey considers him a friend.
- Mr Seymour: Masters mate promoted to acting Third Lieutenant of Nutmeg .
- Horse-Flesh Goffin: Cashiered British post-captain who is captain of the British privateer Triton .
- Mr Nathaniel Martin: Parson, natural philosopher and assistant ship's surgeon aboard HM Hired Vessel Surprise .
- Mr Davidge: Third Mate on HM Hired Vessel Surprise . He attended Trinity College in Dublin like Maturin, and knew the same amount of duelling in those years. He had been a Royal Navy lieutenant, introduced in The Letter of Marque .
- Mr West: Second Mate on HM Hired Vessel Surprise . He had been a Royal Navy lieutenant. He was introduced in The Letter of Marque .
- Sarah and Emily Sweeting: Two young Melanesian girls saved by Maturin, as the last survivors of a smallpox epidemic on Sweeting's Island, and taken aboard.
New South Wales:
- Sir Joseph Banks: Botanist, president of the Royal Society and early promoter of settlement at Botany Bay; mentioned in conversation at the dinner by Maturin and Captain Lowe.
- Lachlan Macquarie: Governor of New South Wales.
- Mrs Macquarie: Governor's wife who welcomes Surprise in her husband's absence
- Captain Lowe: Man aligned with McPherson who insults Maturin and the name of Sir Joseph Banks at the dinner at the Governor's house, resulting in a duel on the spot, which he loses.
- Colonel MacPherson: Deputy to the Governor, and a powerful political force in the dismal colony.
- John 'Anguish' Paulton: A writer and friend of Martin who shares his manuscript with Maturin. He plays music, and spends a pleasant evening with Aubrey as well, both playing their violins.
- Dr Redfern: Humanitarian doctor in the penal settlement.
- Patrick (Padeen) Colman: Prisoner at Botany Bay, formerly assistant to Maturin, found in the hospital after enduring 200 lashes. His crime was theft of laudanum, to which he had become addicted aboard ship, without Maturin noticing. Maturin wants to see and save his shipmate.
- James Fitzgerald: Priest and cousin to Maturin, who reports that the United Irishmen in the penal colony blame him for the hanging of Robert Gough. Maturin explains he never informs, and had nothing to do with Gough being taken (Gough was aboard a snow that Aubrey chased in The Thirteen Gun Salute aboard Surprise but abandoned the chase.)
- Sir William Hastings: Former patient of Maturin who brings him the news that the Naval Chronicle announced the birth of their daughter in April.
