Constance is a young woman working as a companion to the elderly Mrs. Eleanor Fog. After losing her mother to the 1918 flu epidemic and being pushed out of her family's estate, she faces an uncertain future. Having run the estate during the war, she misses the feeling of usefulness and competence she experienced then. She finds herself increasingly drawn to the freedom modeled by the local women's motorcycle club.

Poppy is the unconventional and socioeconomically privileged founder of the Hazelbourne Ladies Motorcycle Club. She operates Wirrall's Conveyance, a business employing lady chauffeurs to counteract the post-war displacement of female workers. Guileless but determined, she advocates fiercely for women's independence and ignores conservative expectations regarding female respectability.

Mrs. Fog is an elderly woman convalescing at the seaside after surviving the flu pandemic. Her recent brush with death has profoundly altered her worldview, making her less interested in adhering to the strict, class-conscious expectations of her past. She becomes increasingly open to progressive ideas and is determined to seize life by reconnecting with figures from her youth.

Harris is a World War I pilot and recent amputee who manages his family's financially strapped estate, Penneston. He struggles with depression and a loss of identity upon returning to a society that prefers to hide wounded veterans. Through his interactions with the motorcycle club and Constance, he slowly attempts to regain his sense of purpose.

Lady Mercer is Mrs. Fog's traditional, aristocratic daughter and a former schoolmate of Constance's mother. She represents the rigid, conservative standards of upper-class British society. Obsessed with appearances and respectability, she frequently attempts to control those around her to protect her family's social standing.

Rachel is Lady Mercer's daughter, a young woman accustomed to privilege and the protection of her social class. She is preparing for a hasty marriage and complies with the traditional roles expected of her, contrasting sharply with the independent women of the motorcycle club.

Percival is an American diplomat and Rachel's fiancé. He holds deeply prejudiced and conservative views, viewing anyone outside his strict social parameters with suspicion and disdain. He is fiercely concerned with maintaining a flawless public image for his impending marriage.

Mrs. Wirrall is a former stage actress and the widow of a baronet. She enjoys the comforts of hotel living and generally adheres to conventional ideas about respectability, though she exhibits a tolerant affection for her children's unusual choices.

Tilly is a member of the Hazelbourne Ladies Motorcycle Club who served as a dispatch rider during the war. To appease her mother's desire for respectability, she works part-time as a librarian, though her true passion lies in repairing motorcycles and supporting the club's activities.

Iris is a former wartime nurse and dispatch rider who co-founded the Hazelbourne Ladies Motorcycle Club. She lives in the barn at Penneston with Poppy and provides motorcycle lessons. She is acutely aware of the double standards women face in the postwar workforce.

Tom is a wealthy, snobbish young man connected to his family's business, Hazelbourne Aviation. He views women's desire to work as a mere novelty and frequently dismisses the capabilities of returning veterans like Harris. He represents the entitled male perspective that expects post-war life to return seamlessly to the pre-war status quo.

Evangeline is Tom's twin sister, an elite young woman who embraces the modern flapper style but lacks emotional warmth. She enjoys her high social status and demonstrates little empathy for those who suffered during the war, preferring to seek out lighthearted amusement.

Guinevere is Tom and Evangeline's sister. Like Evangeline, she dresses in modern, fashionable clothing, but she is generally more courteous and friendly than her siblings, though still insulated by her wealth.

Sam is a polite young man in the Hazelbourne social circle. He is quietly in love with Poppy but struggles to muster the courage to express his feelings. He occasionally displays a condescending, if well-meaning, attitude toward women's wartime contributions.

Mathilde is an old friend of Mrs. Fog who lives near Hazelbourne. She resides quietly with her brother and speaks plainly about the prejudices of upper-class society that have historically impacted her family's life.

Simon is Mathilde's brother and a figure from Mrs. Fog's distant past. He lives a quiet life near the seaside, remaining gentle and devoted despite the societal conventions that previously dictated the course of his relationships.

Captain Pendra is a courteous and warm pilot with the Royal Flying Corps. He is visiting England from India on a trade mission and frequently encounters the casual prejudice and imperialist attitudes of the British establishment, despite his service to the empire.

Mr. Basu is Captain Pendra's colleague on the Indian trade mission. He is irritable and short-tempered, actively frustrated by the British government's efforts to disempower India and exclude its representatives from post-war celebrations.

Klaus is a naturalized British citizen of German descent who works at the Meredith Hotel. He faces intense anti-German prejudice in the aftermath of the war, experiencing a drastic shift in how he is treated by the society he considers his home.

Jock is Harris's former wartime mechanic. Devastated by the loss of his wife and daughters to the influenza pandemic, he struggles with severe grief and alcohol addiction. He requires the intervention of his wartime friends to find a reason to continue living.

Patricia is Constance's friend who works in a London accounting office. She experiences the predatory behavior common in male-dominated workplaces and ultimately chooses the perceived safety of marriage over struggling against systemic barriers.