Principal roles
- Mary Lennox – Lead; girl, about 10. Vocal range roughly Ab3–D5, written as a child soprano/young voice.
- Archibald Craven – Lead; male, 30s–50s. Baritone/tenor with strong mix, about C3–A4 (often notated baritone with optional A4).
- Lily Craven – Archibald’s late wife; adult female. Soprano, often around Bb3–D6 with a legit, floating sound.
Major supporting
- Dr. Neville Craven – Archibald’s brother; adult male. Baritone, commonly around C3–F4/G4.
- Martha – Maid; late teens–20s. Mezzo-soprano/belt, approx. G3–D5.
- Dickon – Martha’s brother; early to late teens. Tenor, typically around C3–G4/A4.
- Colin Craven – Mary’s cousin; boy about 10. Treble/boy soprano, often Ab3–E5 area.
- Ben Weatherstaff – Gardener; mature male. Often listed as baritone or tenor; about C3–G4.
Featured and ensemble roles
- Mrs. Medlock – Housekeeper; adult female. Often a speaking or minimal-singing role; some productions treat her as contralto/low mezzo.
- Mrs. Winthrop – School headmistress; adult female. Generally spoken cameo, sometimes light mezzo.
- Fakir – Indian mystic; male. Tenor, featured in the prologue/ensemble.
- Ayah – Mary’s Indian nurse; female. Alto/mezzo, featured in the prologue/ensemble.
- Captain Albert Lennox – Mary’s father; male. Tenor, appears in prologue and as a “dreamer.”
- Rose Lennox – Mary’s mother; female. Mezzo-soprano, featured/dreamer.
Lieutenants Wright & Shaw, Major Holmes, Claire Holmes, Alice, etc. – Adult ensemble roles covering a mix of tenor, baritone, bass, and soprano lines as the “dreamers” in the prologue and throughout.