| Clive Owen | Dr. John W. Thackery |
| André Holland | Dr. Algernon Edwards |
| Jeremy Bobb | Herman Barrow |
| Juliet Rylance | Cornelia Robertson |
| Eve Hewson | Nurse Lucy Elkins |
| Michael Angarano | Dr. Bertie Chickering Jr. |
| Chris Sullivan | Tom Cleary |
| Cara Seymour | Sister Harriet |
| Eric Johnson | Dr. Everett Gallinger |
| Maya Kazan | Eleanor Gallinger |
| Leon Addison Brown | Jesse Edwards |
| Grainger Hines | Captain August Robertson |
| Charles Aitken | Henry Robertson |
| David Wilson Barnes | Addiction Doctor |
| LaTonya Borsay | Evaline Edwards
(as La Tonya Borsay) |
| Danny Hoch | Bunky Collier |
| John Hodgman | Dr. Henry Cotton |
| Rachel Korine | Junia |
| Tom Lipinski | Phillip Showalter |
| Michael Nathanson | Dr. Levi Zinberg |
| Reg Rogers | Dr. Bertram Chickering, Sr. |
| Frank Wood | Mr. Havershorn |
| Perry Yung | Ping Wu |
| Happy Anderson | Jimmy |
| Michael Berresse | Parke-Davis Representative |
| Lucas Papaelias | Eldon Pouncey |
| Molly Price | Effie Barrow |
| Suzanne Savoy | Victoria Robertson |
| Gary Simpson | Hobart Showalter |
| Martin Brown | |
| Marty Brown | |
| Alfred Cole | Prize Fighter
(as Alfred 'Ice' Cole) |
| Johanna Day | Eunice Showalter |
| Christian Kauffmann | |
| Mandi Masden | |
| Rob Morgan | Diggs Man |
| Rex Peterson | |
| Richard James Porter | Monsignor Joseph Mills Lawlor |
| Juliet Adair Pritner | (as Juliet Pritner) |
| Kim Rideout | Cornelia's Maid |
| Zuzanna Szadkowski | Nurse Pell |
| Ginger A. Taylor | Sonya Smyslov |
| Noelle P. Wilson | Cromartie Nurse |
| Brian Esposito | Choir Boy |
| Jake Allyne | Surgeon /
Groomsman
(uncredited) |
| Brad Bolle | Orderly
(uncredited) |
| Precious Cruz-Dyson | Slave /
Hospital Patient
(uncredited) |
| Chris J. Cullen | Waiter
(uncredited) |
| Susan Gardner | Mistress at Gentlemen's Club (2014)
(uncredited) |
| Steve Garfanti | Surgeon
(uncredited) |
| Logann Grayce | Nurse
(uncredited) |
| Sean Harris | Footman
(uncredited) |
| Robert Lee Harvey | Police Officer
(uncredited) |
| Teddy Kalin | Gallery Viewer
(uncredited) |
| Shana Kaplan | 1900 Pedestrian
(uncredited) |
| Michael J. Knowles | Surgeon
(uncredited) |
| Ari Lew | Pedestrian
(uncredited) |
| Jon Necaj | Newspaper Boy
(uncredited) |
| Jonathan O'Reilly | Tenament Kid
(uncredited) |
| And Palladino | Tenement
(uncredited) |
| Evie Paller | Vendor
(uncredited) |
| Nora Paller | Vendor
(uncredited) |
| Katrina E. Perkins | Women's Asylum Patient
(uncredited) |
| Michael Power | Bar Brawler /
Vendor
(uncredited) |
| Robert Sage | Surgeon
(uncredited) |
| Joseph Scarpino | Gallery Viewer
(uncredited) |
| Frank van Putten | Jeweler
(uncredited) |