The great arms industrialist of Europe. Undershaft returns to his long abandoned family with to wreak havoc with his new gospel of man's salvation. He is a man of "formidable reserves of power, both bodily and mental, in his capacious chest and long head." His gentleness is that of a "strong man who has learnt by experience that his natural grip hurts ordinary people." Undershaft understands that he is a man who has bent the world to his will, and a man who determines the course of civilization and history.
Robust, jolly, and energetic, Barbara begins the play as a major for the Salvation Army. She is peacefully convinced of her mission to redeem mankind. Her father's arrival will force her to recognize that the wealthy, rather than God, hold the world and its salvation in their hands. Undershaft underscores the "inspiration" that truly defines her as the savior of all. The daughter of a foundling, Barbara ostensibly lacks social class and comes "straight from the heart of the whole people."
A "slight, thin haired, and sweet voiced" student of Euripides. Cusins is determined to marry Barbara and enthralled by the excesses and ecstasies of the Dionysian spirit. In his determination, he has joined her in the Salvation Army to bring this spirit to the power, but ultimately converts to Undershaft's gospel, becoming Andrew's heir at the Armory. Shaw describes Cusins as a "determined, tenacious, intolerant person" who presents himself as he is, "considerate, gentle, explanatory, even mild and apologetic, capable possibly of murder, but not of cruelty or coarseness." It is not love that drives him to Barbara, but an unmerciful "instinct."
A "very typical managing matron of the upper class," a woman with "plenty of practical ability and worldly experience." Around fifty years old, she is "limited in the oddest way with domestic and class limitations." Upon Undershaft's arrival, the family—and Stephen in particular—will abandon her as she is too set in her ways to participate in the revolution he brings. Shaw affectionately imagines her through a series of paradoxes: Lady Britomart is at once well dressed and careless in her dress, well bred and reckless of her breeding, well-mannered and yet appallingly outspoken.
Lady Britomart's only son. Stephen is a "gravely correct young man" who takes himself and his sense of morality very seriously. He remains in some awe from his mother from "childish habit and bachelor shyness" but quickly comes to assert his majority in planning his future.
A stereotypical "young man about town." Lomax suffers from a "frivolous sense of humor which plunges him at the most inopportune moments into paroxysms of imperfectly suppressed laughter." A comic figure, he suffers the scolding of Lady Britomart throughout the play for his tactlessness and inarticulate speech. He also repeatedly declares his allegiance to the Anglican Church and other moral platitudes, though these declarations only mask his somewhat mercenary propensity to align himself with the wealthy. He is engaged to Sarah on a lark.
Barbara's younger sister. Sarah is a "slender, bored, and mundane" society girl. She is extraneous to the play.
A young, unemployed, and opportunistic "poser." Price appears incapable of honesty and altruism. He exemplifies the agile "humbugs" that take advantage of the Salvation Army.
Already looking sixty at the age of forty-five, Rummy is a "commonplace old bundle of poverty and hard-worn humanity." Like Price, has embellished on her down-and-out condition to pander to the workers of the Army.
A "half hardened, half worn-out" old-timer. Shirley has just lost his job to a younger laborer. He figures as the play's "honest poor man," weeping in shame over having to take a hand-out, pledging to get back on his feet, and abhorring the injustices of the wealthy.
A "rough customer of about twenty-five" who appears at the Army shelter to reclaim his converted girlfriend and bully its staff. Bill speaks a thick Cockney accent that Shaw marks as "horribly debased" when at its worst. The swaggering, menacing Bill is quickly cowed and disgraced by the shining Major Barbara. Indeed, if not for her father's intervention, Barbara would have won his soul through his devastating humiliation.
An overwrought "Salvation lass" who earnestly believes in her cause and her patron, Major Barbara. She suffers an assault from Bill in Act II.
A Salvation Army Commissioner. Baines is an "earnest looking" middle-aged woman with a "caressing, urgent voice" and an "appealing manner." By accepting the donations of the wealthy as necessary to the work of salvation, she surrenders the Army to millionaires like Bodger and Undershaft.
A foreman at Undershaft's armory.
The longtime family butler who hesitantly announces Undershaft's return to the household.