The four central characters are studies in contrast: the two friends Caroline Helstone and Shirley Keeldar, and their lovers, the brothers Robert and Louis Gérard Moore.
- Robert Gérard Moore – An industrialist whose textile mill is idle because of the war. Perceived as an outsider because he comes from Antwerp, even though he is a cousin of Caroline's. Robert Moore installs new labour-saving machinery in his mill and becomes the target of Luddite attacks.
- Louis Gérard Moore – Robert's brother, working as a tutor for Shirley's uncle.
- Caroline Helstone – A timid and uncertain, but also wise and capable young woman, the niece of Rev. Helstone and best friend of Shirley.
- Shirley Keeldar – An orphaned heiress to a fortune. A headstrong, independent and determined young woman.
Other characters in the novel include:
- Rev. Matthewston Helstone – Caroline's uncle. A fierce man, who is not cruel, but still shows little affection for his niece. Marriage has made him distrustful of women in general.
- Hortense Gérard Moore – Robert and Louis's sister.
- Hiram Yorke – A local landowner.
- Joe Scott – Robert Moore's foreman at the mill.
- Mrs Pryor – Shirley's timid but wise governess, who moves to Fieldhead together with Shirley. She eventually turns out to be Caroline's long-lost mother, Mrs Agnes Helstone.
- The three curates of the three parishes – the Anglo-Irishman Peter Malone, the Cockney Joseph Donne, and the amiable Davy Sweeting.
- William Farren – a hardworking, patient worker. The book's example of the perfect working-class man.
