| 1 | | | New York City, 1913 |
| | Jack | Lyons | The superintendent of the New York Public Library. |
| | Laura | Lyons | Jack Lyons' wife. |
| | Leo | Astor | A stone lion. |
| | Leo | Lennox | A stone lion. |
| | John Jacob | Astor | One of the founders of the library. |
| | James | Lennox | One of the founders of the library. |
| | Harry | | Jack and Laura's son. |
| | Pearl | | Jack and Laura's daughter. |
| | William | Shakespeare | An English playwright, poet, and actor. |
| | Beatrice | | Supposed name of Pearl. |
| | Dr. Edwin H. | Anderson | The library's director. |
| | Edgar Allan | Poe | An American writer, poet, editor, and literary critic. |
| 2 | | | New York City, 1993 |
| | Sadie | Donovan | The assistant curator. |
| | Fiorello | La Guardia | Former Mayor of New York City. |
| | Bal | Thackeray | An Indian politician. |
| | Charles | Dickens | An English writer and social critic. |
| | Walt | Whitman | An American poet, essayist, and journalist. |
| | Henry | Berg | One of the donors of library manuscripts. |
| | Albert | Berg | One of the donors of library manuscripts. |
| | Claude | Racine | Sadie's colleague. |
| | Marlene | Jerkinson | Berg's curator and Sadie's mentor. |
| | Dr. Humphrey | Hooper | The director of the library. |
| | Richard | Jones-Ebbing | One of the new board members. |
| | Mrs. | Smith | One of the new board members. |
| | Mr. | Smith | One of the new board members. |
| | Bob | | A cat. |
| | Cary | Grant | An English-American actor. |
| | Phillip | | Sadie's ex-husband. |
| | Abigail | Duckworth | An author. |
| | Valentina | | Sade's niece. |
| 3 | | | New York City, 1913 |
| | Billy | | Jack Lyons' friend. |
| | Auguste | Rodin | A French sculptor. |
| | Joseph | Pulitzer | A newspaper publisher. |
| | Talcott | Williams | The head of Columbian Journalism School. |
| | George | Wakeman | A professor at the Columbian University School of Journalism. |
| | Gretchen | Reynolds | One of Laura's classmates at Columbian Journalism School. |
| | Larry | Kline | The former mayor of Hawkins. |
| 4 | | | New York City, 1913 |
| | Edwin | Gaillard | The library detective. |
| | Thomas | Jefferson | 3rd U.S. President. |
| 5 | | | New York City, 1993 |
| | Mr. | Babenko | A longtime employee at the library. |
| | Lonnie | | Sadie's brother. |
| | LuAnn | | Lonnie's wife. |
| | Robin | Larkin | A baby sitter. |
| | Don | | Pearl's second husband. |
| | Virginia | Woolf | An English writer. |
| 6 | | | New York City, 1993 |
| | Fred | Astaire | An American actor, dancer, singer, choreographer. |
| | Hilary | Quinn | Laura Lyon's former secretary and executor in London. |
| 7 | | | New York City, 1913 |
| | Mrs. | Marino | One of the mothers at tenement. |
| | Dr. Amelia | Potter | Worked from the city as medical inspector. |
| | Kate | Chopin | An American author of short stories and novels. |
| 8 | | | New York City, 1914 |
| | Henrietta | | Amelia's acquaintance. |
| | Margaret | Sanger | One of the members of the Heterodoxy Club. |
| | Florence | | One of the members of the Heterodoxy Club. |
| | Jessie | | Amelia's partner. |
| 9 | | | New York City, 1993 |
| | Nick | Adriano | A security consultant. |
| | John | Ashbery | An American poet and art critic. |
| | Professor | Ashton | A college mentor. |
| 10 | | | New York City, 1993 |
| | Max | | A dog. |
| 11 | | | New York City, 1914 |
| | Max | Eastman | An American writer on literature, philosophy and society. |
| | Ida | | Max Eastman's wife. |
| | Alexander | Hamilton | Founding Father of the United States. |
| | Washington | Irving | An American short-story writer, essayist, biographer, and historian. |
| | Joseph G. | Cogswell | The first superintendent of Astor Library. |
| 12 | | | New York City, 1914 |
| | Mabel | Dodge | Amelia's acquaintance. |
| | Elizabeth G. | Flynn | One of the members of the Heterodoxy Club. |
| | Emma | Goldman | One of the members of the Heterodoxy Club. |
| | Alfred | Stieglitz | American photographer. |
| | Frank | Tannenbaum | An Austrian-American historian, sociologist and criminologist. |
| 13 | | | New York City, 1993 |
| | Nathaniel | Hawthorne | An American novelist, dark romantic, and a short story writer. |
| | Chuck | | The owner of J&M Books. |
| | Joan | Blaeu | A Dutch cartographer. |
| | Dorothy | Parker | An American poet, writer, critic, and satirist. |
| | Elaine | Edmundson | The name used by Sadie when buying the lost books. |
| 14 | | | New York City, 1993 |
| | Inspector | Clouseau | Berg Collection's inspector. |
| | Wendy | Wasserstein | An American playwright. |
| | Sue | | Nick Adriano's wife. |
| | Sebastian | | Nick's dog. |
| 15 | | | New York City, 1914 |
| | Inez Haynes | Gillmore | One of the members of the Heterodoxy Club. |
| 16 | | | New York City, 1914 |
| | Marie Jenney | Howe | A feminist organizer and writer. |
| 17 | | | New York City, 1993 |
| | Mr. | Blount | Claude's acquaintance. |
| 18 | | | New York City, 1993 |
| | Charlotte | Bronte | An English novelist and poet. |
| 19 | | | New York City, 1914 |
| | Alva | Belmont | One of the leaders of the New York suffrage movement. |
| | John Merven | Carrere | One of the building's architect. |
| | Thomas | Hastings | One of the building's architect. |
| 20 | | | New York City, 1914 |
| | Dr. | Bell | Harry's physician. |
| | Sam | | Harry's classmate. |
| | Red | Paddy | Harry's acquaintance. |
| | George | Washington | 1st U.S. President. |
| 22 | | | London, 1993 |
| | Leonard | | Canadian singer-songwriter. |
| 24 | | | New York City, 1914 |
| | Mr. | Benson | The janitor. |
| 26 | | | New York City, 1918 |
| | Sarah | | Pearl's friend. |
| 27 | | | New York City, 1993 |
| | Jack | Kerouac | An American novelist. |
| | Vladimir | Nabokov | A Russian-American novelist, poet, translator and entomologist. |
| 28 | | | New York City, 1993 |
| | Jane | Austen | An English novelist. |
| | Alfred | Tennyson | A British poet. |
| | William Butler | Yeats | An Irish poet. |
| | Lesley | Stahl | An American journalist. |
| | | Kiernan | A judge. |