Roebuck Ramsden
Ramsden is a middle-aged gentleman who considers himself an intellectual pioneer and a progressive thinker, though in truth, he has a conservative approach to politics and social life. Indeed, he clings to once-new ideas advanced by Victorians such as Charles Darwin, believing that this makes him an intellectually open person even while he closes himself off to newer theories and concepts. George Bernard Shaw carefully evokes Ramsden's clothing, home, and family in order to show how deeply conformist he actually is, and Shaw even notes in stage directions that Ramsden shows a certain "expectation of deference." An old friend of Ann's father, Ramsden is one of the two men assigned to care for her and her sister. He means well and cares deeply about Ann, but his ideological differences from the nontraditional Jack Tanner become a distraction for him. Vain and oblivious though he can be, Ramsden is fairly harmless and serves mostly as a foil to Jack Tanner.
Octavius Robinson
Octavius is a young, orphaned bachelor in the social circle of the Ramsdens, the Whitefields, and Jack Tanner. Though he's close with Jack, he shares few of his friend's fiery attitudes. Instead, he's an artistic soul with the goal of becoming a poet. He's also a hopeless romantic, and has been in love with Ann Whitefield for years. Because of his trusting attitude, other characters, especially Jack and Ann, find him both lovable and easy to deceive. Octavius is also Violet Robinson's brother, though in many ways, he displays more stereotypically feminine traits while hers are more stereotypically masculine. Therefore, though he feels protective of her, Violet is unwilling to be the object of pity. Octavius, on the other hand, somewhat enjoys the emotional intensity of self-pity, causing Ann to remark that he will be happiest as a lifelong bachelor.
Ann Whitefield
Ann is the older daughter of Mr. Whitefield, whose death is the catalyst for most of the play's action. She is based on the character of Dona Ana de Ulloa in the original Don Juan story, and is represented by an old woman, Ana, during Tanner's Don Juan dream sequence. However, the ways in which Ann contrasts with the innocent piety of Ana serve as a commentary on modern womanhood. Ann is neither innocent nor churchgoing. Rather, she's pragmatic to a fault, and has no qualms about manipulating others in order to get her way. Therefore, she's able to convince Tanner to marry her, and able to convince Octavius that he'll be better off without her. She often claims that her own desires are actually commands from her parents, allowing her to preserve her reputation as an innocent, obedient young woman while actually getting the things she wants. In contrast with her counterpart, Ana, Ann has the contemporary woman's ability to pursue her own goals and even to exert control over others. However, the virtuous femininity of characters like Ana casts a shadow on Ann's own society, and, knowing this, she does her best to seem as innocent as possible in order to gain sympathy from men.
John/Jack Tanner
Jack Tanner, a left-wing thinker and author of the book The Revolutionist's Handbook, is one of the men left in charge of Ann Whitefield after her father's death. He naturally draws attention with his charisma and provocative statements. Tanner corresponds with the figure of Don Juan himself, and has a long dream in which he actually becomes Don Juan. The ideas espoused by Don Juan in the dream and by Tanner in waking life are similar: both reject conformist thinking and the pursuit of comfort, choosing instead to seek out "life-force" and to pursue self-improvement with the goal of becoming an enlightened "Superman." Though Shaw generally positions Tanner as the moral center of the play, his intensity and passion can be almost comic at times, or can appear counterproductive. For instance, he assures Violet that she needn't be ashamed of her pregnancy, but clarifies that this belief stems, not from sympathy with Violet, but from a belief that women's sole purpose is reproduction. The play's strangest and most complex character, Tanner eventually falls in love with Ann in spite of his initial determination never to marry, having become convinced that marrying Ann is the inevitable result of the life-force.
Violet Robinson
Violet is the sister of Octavius. She becomes pregnant at the beginning of the play, and is secretly married to Hector Malone, Jr. Like Ann, she is able to get almost everything she wants, but her chosen tool is not manipulation; instead, she's extremely direct, and doesn't hesitate to tell others when she disagrees with them. At the start of the play, when Roebuck Ramsden and other traditionally-minded characters condemn her pregnancy, Violet tells them that they've insulted her and then stubbornly refuses to reveal her husband's identity. Later, when her husband's father tells her that she isn't wealthy enough to marry his son, she coolly points out his prejudiced attitude. People tend to listen to Violet and to respect her, even if they don't like her. In this way, she contrasts with her brother, who is beloved, but not widely treated with respect.
Henry Straker
A working-class driver from London, Henry Straker speaks with a distinct Cockney accent, which is the root of his nickname—the Cockney-esque "'Enry." He's a straightforward and fairly literal person whose job and personality help highlight, through contrast, some of the more high-flown or hypocritical notions held by his employers. After all, Straker is not only a worker, but a technological expert who prizes efficiency and speed over painstaking work, thus undermining some of the more romanticized visions of the worker that Jack and Octavius hold. In spite of their differences, Henry and the play's upper-class characters get along well: they rely on him to a great deal, and he regards them with skeptical but respectful distance. In a strange twist, Henry also finds out that Mendoza is in love with his sister Louisa, giving him a more personal stake in some of the play's events.
Mendoza
This socialist/anarchist revolutionary has an outsize personality—he's witty, intelligent, articulate, and a hopeless romantic with an enormous crush on Henry Straker's sister Louisa. While some of the play's politically-minded characters, such as Jack Tanner, have a more academic approach, Mendoza likes to get right to the source of inequality by kidnapping and robbing the rich in order to redistribute their money. He manages to persuade a loose band of others to help him with this, including, eventually, Hector Malone Sr., who invests in Mendoza's efforts. Mendoza is also Jewish and announces this fact, showing that he is not only an outsider, but a proud one.
Hector Malone Jr.
The son of Hector Malone Sr, he is married to Violet. Unlike his wife, Hector is romantic rather than practical. He values notions of honor so deeply that he becomes comical. For instance, he insists, unrealistically, that he will become financially independent on his own for the sake of marrying Violet, and has to be circumvented by his wife and father. Generally, though Malone means well enough, Shaw does not take him particularly seriously. Since he is only native-born American in the play, Malone's vices to a degree implicate all of his countrymen and his culture more broadly.
Hector Malone Sr.
Hector Malone Sr., Violet's father-in-law (though he himself is unaware of this status for much of the play) is an American billionaire. Born in Ireland and displaced by the potato famine as a child, Malone very much wants to prove himself to the world at large and to the English upper classes in particular. As a result, he is determined to have his son marry an aristocrat, although he ends up feeling satisfied with Violet because of her tough and intelligent personality. This rigid materialism makes Malone something of an avatar of the ruling class. Though he has far more wealth than he needs, he pursues even more wealth and status out of a misguided desire for revenge rather than out of actual hope for his son's well-being.
Mrs. Whitefield
The widow of Mr. Whitefield and Ann's mother, Mrs. Whitefield is notable mainly for her inability or unwillingness to control her daughter. She is easily bullied by Ann, even though she occasionally voices disagreement by criticizing her daughter's choices. Shaw makes clear even in his stage directions that Mrs. Whitefield should be nonthreatening and powerless. She is childlike and small, with a high voice. Therefore, though Ann is not technically orphaned, her parents make few influential decisions, giving her an extraordinary amount of freedom.
Susan Ramsden
Susan, also called Miss Ramsden, is Roebuck's unmarried sister. She is conventional and morally rigid, and therefore opposed to helping Violet during her unplanned pregnancy.
