The Main, Plain, and Inane
- Mrs. Ashton-Dennis: Cassandra Ashton-Dennis’s mother
- Revd Ashton-Dennis: Cassandra Ashton-Dennis’s late father
- George Ashton-Dennis (Goulding): Cassandra’s wealthy entitled brother, adopted by the Gouldings
- Penelope ‘Pen’Ashton-Dennis (Goulding): George Ashton-Dennis’s eldest daughter
- Ned ‘Neddy’ Ashton-Dennis (Goulding): George Ashton-Dennis’s son
- Estella ‘Stella’ Romney: Charles Romney’s sister and Penelope Ashton-Dennis’s fond friend and confidante
- Louisa and Mary Niven: Cassandra Ashton-Dennis’s close neighborhood friends and residents of ‘Heathmore’
- Sam Prentice: Winston Prentice’s son and scion and close friend of the Ashton-Dennis family, most particularly of Fulwar and Lawrence Ashton-Dennis
- Fanny Alveston: Thomas Alveston’s wife
- Madame Belgonie: Charlotte de Lafayette’s French lady’s maid and companion
- The Hon. Norah Morgan: Lord Lamington’s first wife
- Mrs. Goulding: George Ashton-Dennis’s benefactress and adoptive mother
- Lord Chesterton: Terry Alveston’s benefactor
- Lila Halyard: Charlotte de Lafayette’s late mother
- Saul Halyard: Charlotte de Lafayette’s late father
- Stirling Tyler: Louisa Niven’s primary suitor
- James Stilworthy: Louisa Niven’s secondary suitor
- Dr. Lascelles: John Lascelles’s uncle and married to Susan Lascelles
- Warren Tierney: The Regent’s court physician and Penelope Ashton-Dennis’s first suitor
- Dr. Guilford: The Ashton-Dennis’s family doctor
- Lionel Seymour: Cassandra Ashton-Dennis’s first would-be London publisher
- Robert Hall: Cassandra Ashton-Dennis’s second London publisher and Military Library connection of Lawrence Ashton-Dennis
- Mr. Niven-Walters: Harry Niven-Walters’ and Louisa and Mary Niven’s father
- Stanley Trilling: Lawrence Ashton-Dennis’s banking partner
- Irvine Marston: Lawrence Ashton-Dennis’s banking partner
- Lord & Lady Burton, Mr. Burton: The Ashton-Dennis’s neighbors and family acquaintances in Gouldham
- The Marches: The Ashton-Dennis’s neighbors and family acquaintances in Gouldham
- Miss Burnett: A London acquaintance of Lawrence Ashton-Dennis
- Miss Lamb: A London singer
- Miss Coombe-Davis: A London singer
- Mr. Trumwell: A surgeon-chaplain in the service of the British navy
- Monsieur Haliberte: Charlotte de Lafayette’s chef
- Jenny: The Ashton-Dennis’s maidservant at Gouldham Cottage
- Miles: Charles Romney’s coachman
- Joseph Wood: George Ashton-Dennis’s carpenter