| 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 |
| David Fierro | Inspector Jacob Speight |
| Leon Addison Brown | Jesse Edwards |
| Matt Frewer | Dr. J.M. Christiansen |
| Melissa Errico | Catherine Christiansen |
| Collin Meath | Phinny Sears |
| Lucas Papaelias | Eldon Pouncey |
| Frank Wood | Mr. Havershorn |
| Michael Berresse | Parke-Davis Representative |
| Karl Bury | Mr. Corker |
| Louis Butelli | Mr. Gentile |
| Christopher Dalbey | Bleier Driver |
| Kate Easton | Mrs. Warren |
| Cait Cortelyou | Nurse Monk
(as Caitlin Johnston) |
| Lucy Jurevics | Yetta Krawetz |
| Ying Ying Li | Lin-Lin |
| Caitlin McDonough-Thayer | Miss Telfer |
| Richard James Porter | Monsignor Joseph Mills Lawlor |
| Martins Straupe | Mr. Krawetz |
| Monty Stuart | Pete |
| Aija Terauda | Mrs. Krawetz |
| Zenon Zeleniuch | Slum Landlord |
| Fred Broadbent | Doctor
(uncredited) |
| Jedidiah Dore | Business Man
(uncredited) |
| Julia M. Ebner | Krawetz Kid
(uncredited) |
| Joe Fionda | Gallery Viewer
(uncredited) |
| Henry Gagliardi | Krawetz Kid
(uncredited) |
| Logann Grayce | Nurse
(uncredited) |
| Kurt Grube | Mourner
(uncredited) |
| Sean Harris | Footman
(uncredited) |
| Teddy Kalin | Wedding Guest
(uncredited) |
| Shana Kaplan | 1900 Pedestrian
(uncredited) |
| Jordana Keller | Krawetz Kid
(uncredited) |
| Jenna Rae Montgomery | Boardroom Secretary
(uncredited) |
| Andrew Paterini | Tenament
(uncredited) |
| Joseph Scarpino | Gallery Viewer
(uncredited) |
| Robert Shulman | Gallery Viewer
(uncredited) |
| Cris Williams | Opium Den Patron
(uncredited) |