In order of appearance:
- Mr Paul Dombey: The main character, about 48 years old as the novel opens. 'In all his life, he had never made a friend. His cold and distant nature had neither sought one, nor found one'. He is left a widower with two children by the end of Chapter 1. However, he only considers his son, Paul, to be worthy of his attention; his daughter, Florence, is 'merely a piece of base coin that couldn't be invested — a bad boy.' The son's death shatters Mr. Dombey's hopes for an heir. His neglect of his daughter Florence causes problems with his second wife, Edith, whom he essentially purchased. Due to Edith's hatred for him and his own misplaced trust in James Carker, Dombey loses his business and his wealth. Dombey finally realises that his daughter was the only person who truly cared for him, even when he has nothing left. He reconnects with her in his later years and gains an heir through his son-in-law.
- Mrs Fanny Dombey: Mr Dombey's first wife, mother of Florence and Paul; dies soon after Paul is born
- Master Paul Dombey (Little Dombey): Born as the novel begins; he is weak and often ill. A gentle child, he is adored by his sister Florence and beloved of his schoolmates. He dies of an unspecified illness in Chapter 16.
- Miss Florence (Floy) Dombey: Mr Dombey's daughter, about 6 years old as the novel begins. She dotes on her little brother. Despite her father's neglect, which amounts to emotional abuse, she loves him and longs for some return of her affection. During an unauthorized outing with Mrs Richards (Toodle), she is snatched from the street by Good Mrs Brown. After her father's wedding to Edith, she bonds with her stepmother. Florence flees the house when she realizes that Edith has broken with her father, taking refuge with Captain Cuttle at The Wooden Midshipman. She eventually marries Walter Gay and bears him two children.
- Dr Parker Peps: One of the Court Physicians, pompously confuses Mrs Dombey's name with the names of aristocrats whom he has treated
- Mrs Blockitt: Nurse, 'a simpering piece of faded gentility'
- Mr Pilkins: Physician of the Dombey family, defers obsequiously to Dr Peps
- Mrs Louisa Dombey Chick: Mr Dombey's sister; an anemic copy of her brother, who is also the only person for whom she has any affection.
- Miss Lucretia Tox: Friend of Mrs Chick until their falling-out, great admirer of Mr Dombey, and neighbour of Major Bagstock
- Mr John Chick: Husband of Mrs Chick
- Mr Toodle: A locomotive stoker
- Mrs Polly Toodle (Richards): Fertile wife of Mr Toodle, engaged as nurse to young Paul. Mr Dombey wants her to use 'an ordinary name, and convenient' while in his employ and thus requires her to answer to the name of Richards. During an ill-advised visit to her home in Staggs's Gardens, Florence is temporarily taken by Good Mrs Brown. Mr Dombey is undisturbed by the loss of his daughter in the urban crowd, but is incensed that Mrs Richards dared to take his son 'to such vile haunts' and summarily discharges her. Later she is brought back by Captain Cuttle to keep house at The Wooden Midshipman
- Robin Toodle (Rob the Grinder, Biler): Son of Mr Toodle and Polly. Sent to the Charitable Grinders school through Mr Dombey's largesse, he cannot resist the lure of tending pigeons and skips school. A pathetic boy, Rob is manipulated by the adults and cannot find a way to better his lot. He is forced by Mr Carker the Manager to spy on Captain Cuttle and report the comings and goings at The Wooden Midshipman. After Carker absconds late in the book, Rob is forced by Good Mrs Brown to bring her information concerning the location in France to which Carker and Mrs Dombey have fled.
- Miss Susan Nipper: Florence's spitfire loyal nurse, about 14 years old at the time of her introduction to the reader. She believes that 'childhood, like money, must be shaken and rattled and jostled about a good deal to keep it bright'. After about ten years, she impudently berates Mr Dombey for his emotional neglect of his daughter and is summarily dismissed from the house. She is later joyfully reunited with Florence at The Wooden Midshipman and eventually marries Mr Toots.
- Solomon (Uncle Sol) Gills: 'An elderly gentleman in a Welsh wig', maker of and dealer in ships' instruments, proprietor of The Wooden Midshipman. He goes missing while searching for his nephew Walter in the Caribbean but returns late in the book.
- Walter (Wally, Wal'r) Gay: Nephew of Solomon Gills, employee of Mr Dombey, about 14 years old at the time of introduction to the reader. Vindictively sent to Barbados by Mr Carker the Manager. Long feared to have been lost at sea, he reappears in Chapter 49. Bears a deep affection for Florence ever since rescuing her from Good Mrs Brown
- Captain Edward (Ned) Cuttle: Retired hook-handed sea captain and friend of Solomon Gills. Terrified of his landlady Mrs MacStinger, he sneaks out of her house and moves into The Wooden Midshipman. He loyally keeps the shop running during Walter and Uncle Sol's absence and provides refuge for Florence after she flees her father's house.
- Good Mrs Brown: An elderly rag dealer who briefly kidnaps the young Florence from a street crowd and steals her fine clothes. She only refrains from cutting off Florence's hair because she has a daughter of her own who's 'far away', a piece of foreshadowing for the appearance of Alice later in the book. Greedily provides Mr Dombey with Rob the Grinder's information on where his wife and Mr Carker the Manager have fled.
- John Carker (Mr Carker the Junior): Older brother of James, disgraced himself by stealing from the firm of Dombey and Son during the time Mr Dombey's father was running it. 'Not old but his hair was white; his body was bent or bowed' with 'deep lines in his worn and melancholy face'. Called 'The Junior' to designate his place in the firm, not in relation to his (younger) brother
- Major Joseph Bagstock: Conceited retired army major. 'Wooden-featured, blue-faced' with 'long-flapped elephantine ears', he refers to himself annoyingly in the third person as Josh, Joe, Joey B., J.B., Old Joe, etc. He befriends Mr Dombey at Brighton, and fatefully introduces him to Mrs Skewton and her daughter. Bagstock convinces himself that Miss Tox finds him appealing when in reality she has eyes only for Mr Dombey.
- The Native: Bagstock's servant who comes from an unspecified country, presumably a British colony, and has 'no particular name, but answered to any vituperative epithet'. Mistreated by Bagstock relentlessly
- Mrs Wickam: Replacement as young Paul's nurse after the disgrace and dismissal of Mrs Richards, 'a meek woman, of a fair complexion, with her eyebrows always elevated, and her head always drooping'
- Mrs Pipchin: Stern widow who keeps an 'infantine Boarding-House of a very select description' in Brighton, where Paul is sent for his health. 'A marvellous ill-favored, ill-conditioned old lady, of a stooping figure, with a mottled face, like bad marble'. An implacable enemy of Susan Nipper, she later heads the Dombey household
- Master Bitherstone: Another child at Mrs. Pipchin's, where he receives ill treatment from the proprietress. Much later a student at Doctor Blimber's
- Miss Pankey: Another child at Mrs. Pipchin's, 'was shampoo'd every morning, and seemed in danger of being rubbed away altogether'
- Mr Brogley: Dealer in second-hand goods and broker. 'A moist-eyed, pink-complexioned, crisp-haired man of a bulky figure, and an easy temper'. He demands payment on a bond of Mr Gills's, forcing the latter to consider the desperate move of selling all his merchandise.
- Mrs MacStinger: Lets rooms in her building in the docklands of the East End; Captain Cuttle's fierce landlady and nemesis
- Doctor Blimber: Operates a school in Brighton ('a great hot-house, in which there was a forcing apparatus incessantly at work') which Paul briefly attends
- Mr P. Toots: The oldest student at Dr Blimber's school, 'possessed of the gruffest of voices and the shrillest of minds', something of a dandy ('people did say ... that when he began to have whiskers he left off having brains'). Often becomes tongue-tied and strings together nearly nonsensical series of words. In love with Florence, but miserably backs off upon learning of her attachment to Walter Gay. He finds happiness at the end of book in marriage to Susan Nipper.
- Mrs Blimber: Doctor Blimber's wife
- Miss Cornelia Blimber: Doctor Blimber's daughter, teacher at the school, later married to Mr Feeder
- Mr Feeder, B.A.: Doctor Blimber's assistant, teacher at the school and later its owner. 'In the habit of shaving his head for coolness, and had nothing but bristles on it'
- Briggs: Another boy at Doctor Blimber's school, 'the stony boy'
- Tozer: Another boy at Doctor Blimber's school
- Mr Perch: Messenger in Mr Dombey's business, always hurries to prepare Mr Dombey's office when the latter comes through the front door. Considered an irritant by Susan Nipper
- Mr Morfin: Assistant manager in Mr Dombey's business. He plays 'cello and participates in 'quartettes of the most tormenting and excruciating nature ... every Wednesday evening'. Brings aid to John Carker and his sister Harriett late in the book
- James Carker (Mr Carker the Manager): Devious manager in Mr Dombey's business, smiles constantly in a way that exposes all his teeth. 'Sly of manner, sharp of tooth, soft of foot, watchful of eye, oily of tongue, cruel of heart, nice of habit'. He physically abuses Rob the Grinder and sends him to spy on the goings-on at The Wooden Midshipman. While appearing loyally to serve Mr Dombey for years, he has actually been self-dealing. He manipulates Edith Dombey into meeting him in France, but is shocked to learn that Mr Dombey has discovered his whereabouts and is pursuing him. He is killed by a train after seeing Mr Dombey on the platform.
- Sir Barnet Skettles: Attends Dr Blimber's dance with his wife and child where he converses with Mr Baps about the latter's work with 'figures'. Sir Barnet then learns from Dr Blimber that Mr Baps is in fact a dancing master, thus revealing that the 'figures' referred to were not the ones Sir Barnet had assumed. He flies into 'a perfect rage' and glowers at Mr Baps.
- Lady Skettles: wife of Sir Barnet
- Master Skettles: Brighton school pupil
- Diogenes (Di): A large dog from Dr Blimber's school, befriended by Paul and adopted by Florence after Paul's death. Follows Florence when she flees her father's household
- Mr Towlinson: Mr Dombey's butler
- Mrs Skewton ('Cleopatra'): Seventy years old but dresses as if she were 20. Introduced to Mr Dombey by her old friend Major Bagstock at Leamington. Amibitious for herself and her daughter, she urges Edith to marry Mr Dombey. Has a stroke and later dies
- Edith Skewton Granger: Chilly, haughty beauty, daughter of Mrs Skewton, widow of an army officer, lost a small son to drowning. Becomes second Mrs Dombey. The conflict between Edith’s pride and Mr. Dombey’s is a key element of the story. She and her mother have had prior financial dealings with Mr Carker the Manager and Edith dislikes him intensely. She is determined that her unspoiled, innocent stepdaughter Florence will not suffer her fate of essentially being sold to men. After abandoning Mr Dombey in a rage of resentment, she is later partially reconciled to him through the intervention of Florence in a very poignant parting scene between Edith and Florence at the end of the book.
- The Game Chicken: boxer and rowdy companion of Mr Toots
- Jack Bunsby: captain of the Cautious Clara; taciturn but regarded as an oracle by Captain Cuttle, eventually wedded to Mrs MacStinger
- Cousin Feenix: Relative of the Skewtons. Returning from the spa at Baden-Baden, he drunkenly toasts Edith's marriage to Dombey. The couple live in his house while the Dombey mansion is being renovated.
- Miss Harriet Carker: Sister of James and John, disowned by James for taking John's side in the wake of the latter's disgrace
- Alice: daughter of Mrs Brown, recently returned from transportation. Nurses a deep hatred of all the Carkers owing to having been once used as a sex object and discarded by Mr Carker the Manager, who then refused to aid her when she got in trouble with the law. Eventually reconciles with Harriet