Dora Bastable
Dora is the eldest of the six Bastable children and is thought by her siblings to be far too responsible and too much like an adult. Dora knows this and it upsets her, as she is merely doing what their mother asked her to do shortly before she passed away and is taking her role as their moral guardian very seriously. Many of the more outlandish exploits take place when Dora is otherwise occupied because her siblings don't want her to put a damper on their adventure. Dora is immensely supportive and maternal when it comes to her brothers and sister but this is quite a lonely position to be in as there is nobody acting in that mother role for her.
Oswald Bastable
Oswald is the oldest boy and is also the narrator of the novel. He believes that he is keeping his identity a secret but his habit of singing "Oswald's" praises as the impartial narrator and this reveals his identity without him really meaning to. From Oswald's narration we learn that he won the Latin prize at school, that he is dazzlingly insightful for a boy of his age, that he is far more considerate than most children and that he is given to having far better ideas than his siblings. From the actual interactions between the children we also learn that he is very fair, that he would not upset them for the world and that he is the family peacemaker, generous with mollifying words and willing to split toys, gadgets and rewards with the others. Oswald is polite and believes manners are important and is already aware that his behavior and gentlemanliness reflect on his parents.
Alice Bastable
Alice is a tomboy and always picks our a male part for herself in their games of adventure. She seems to identify with boys more than girls, keeping her hair short and preferring to play games with her brothers than join in more traditionally "girly" pursuits with her sister. Alice loves the dramatic and her idea to seek treasure using a divining rod appeals to her mainly because she gets to wear a priestess costume. Alice is feisty and brave and never hangs back behind her brothers.
Noel Bastable
Noel is a creative, sensitive soul who writes piety and wants to be a famous poet or an editor. Although his siblings are rather skeptical about the treasure-seeking potential of his poetry, he does have some success and manages to sell some poems to the editor ofThe Recorder, also opening the door for them to sell some human interest snippets about Lord Tottwnham. Noel is a sickly boy who is not in the best of health and prone to colds, chills and general weakness.
Dicky Bastable
Dicky is good at sums and likes facts, nicknamed "the definite article" by his father.He can be disagreeable and quarrels quite frequently with Dora because she disapproves of his most fun ideas. He doesn't like to show his hand or contribute half-formulated ideas to the conversatipn. Dicky is convinced that their best chance of finding treasure is to invest in one of the work from home schemes advertised in the evening paper. He is fairly patient in waiting for the others to give his plan a try but when they do eventually do this their doubts are justified as it doesn't bring in any treasures to the House of Bastable at all.
H.O. Bastable
Horace Octvius is called H.O. By his family and friends and is sometimes babied by his older siblings and Oswald is personally concerned that H.O. Is becoming a milksop and that he is acting in a way that is far more babyish than he knows perfectly well is expected of him. His treasure seeking scheme is becoming a bandit which he knows is rather dubious and wrong but also feels that if they are pretending to be bandits then it is not really bad at all. He is always keen to participate and loves any scheme that enables him to get muddy and dirty.
Father
The children's father is a widower and has lost both his wife and a good percentage of the family's income at the same time. He loves his children and although he expects a lot of them he is also fair and loving. The exact nature of his business is not specified but he is struggling to make ends meet and it seems that the harder he works the worse his financial situation becomes. He is unable to pay most of the family bills but at the same time tries to shield his. Holden from this and really would prefer that they not be so aware that money is short. Happily at the end of the novel his new partnership with their Indian uncle restores the House of Bastable's fortunes.
Albert-Next-Door
Albert is the Bastable's neighbor and playmate but he is a very soft boy prone to crying and screaming. He is not particularly fun because he has no spirit of adventure, hates to get dirty and is always more concerned about getting home in time for tea than about playing or making friends. His lack of gumption does not only frustrate the Bastable kids - he also frustrates his uncle who thinks he needs to toughen up. Albert refuses to throw himself into the spirit of a game and makes an appalling pretend hostage once the Bastable's have pretended to kidnap him.
Albert's Uncle
Albert's uncle is a writer and the children live the way he talks like a character in a book as well. He always has time for the Bastable children and is good at giving advice with kindness whilst simultaneously keeping them I the straight and narrow. He is generous, taking Noel to the coast to help him recuperate from his cold, and dropping money in the treasure hole in the garden to make the children believe they actually struck gold.
Eliza
Eliza is the Bastable's housekeeper but her housekeeping skills leave a lot to be desired. She is not a very good cook and burns much of the food she makes; her sauces are usually lumpy but she makes the food they have go a long way. Eliza, like the housekeepers before her, is a little light fingered with coins and silverware. Oswald believes her to be lacking in cleanliness as her ears look dirty and he believes this is why she does not clean the house very well.
Indian Uncle
The children's Indian uncle is kind and generous, bestowing beautiful gifts on everybody and sharing his illustrious home with them, thereby restoring the fortunes of the House of Bastable. He is not at all stuffy and enjoys entering into the spirit of games of pretending with the children, helping to trap and kill their dinner and chivalrously overpowering a fruit pudding. He enjoys the company of a family and is a genuine, giving person who ends up being the treasure they are seeking.
