| 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 |
| Zaraah Abrahams | Opal Edwards |
| Charles Aitken | Henry Robertson |
| LaTonya Borsay | Evaline Edwards |
| Rachel Korine | Junia |
| Tom Lipinski | Phillip Showalter |
| Michael Nathanson | Dr. Levi Zinberg |
| Phil Burke | Doctor |
| Will Brill | Leo Guggenheim |
| Michael Cumpsty | Judge Parkinson Bothamly |
| Jennifer Ferrin | Abigail Alford |
| Gibson Frazier | Harold Prettyman |
| Arielle Goldman | Genevieve Everidge |
| Andrew Rannells | Frazier H. Wingo |
| Anthony Rapp | Dr. Thurman Drexler |
| Stephen Spinella | A.D. Elkins |
| Happy Anderson | Jimmy |
| Annabelle Attanasio | Dorothy Walcott |
| Jason Babinsky | Mt. Sinai Doctor |
| Jarlath Conroy | The Hypnotist |
| Gia Crovatin | Clara Horner |
| Ylfa Edelstein | Nurse Baker |
| Marshall Elliott | (as Marshall Elliot) |
| Miranda Gruss | Zoya |
| Rebecca Gruss | Nika |
| Sydney Hollis | Bailiff |
| Joshua Johnson | |
| David Kubicka | Griscom |
| Ben Livingston | Dr. William H. Mays |
| James Lyden | |
| Kate MacCluggage | Mary |
| Jerry Miller | Cromartie Orderly |
| Ciarán O'Reilly | Priest
(as Ciaran O'Reilly) |
| Lucas Papaelias | Eldon Pouncey |
| Alexandra Roxo | Cate |
| David Sedgwick | Mr. Horner |
| Zuzanna Szadkowski | Nurse Pell |
| Mitch Vallen | Otto
(as Mitchell Vallen) |
| Gillian Williams | Henny |
| Kelly Aaron | Society Lady |
| Tyler Caffall | The Fire-tender |
| Terrence Clowe | Floor Dancer |
| Constantine Kefalogiannis | Doctor |
| Norman Aaronson | Pretzel Buyer
(uncredited) |
| John Paul Cayetano | Horse Wrangler
(uncredited) |
| Shane Copland | Wrestling Timekeper
(uncredited) |
| Vin Hamilton | Operating Theater Reporter
(uncredited) |
| Sean Harris | Footman
(uncredited) |
| Jesse Jantzen | Referee
(uncredited) |
| Sven Jähnert | Construction Worker
(uncredited) |
| Nicole Kontolefa | Mrs. Horner
(uncredited) |
| Dillon Mathews | Doctor
(uncredited) |
| And Palladino | Gallery Doctor
(uncredited) |
| Christina Paterno | Nurse
(uncredited) |
| Katrina E. Perkins | Upper Class Pedestrian
(uncredited) |
| Robert Sage | Surgeon
(uncredited) |
| Christian Paul Sherwood | Patient
(uncredited) |
| Tom Stratford | Immirgrant
(uncredited) |
| Yury Tsykun | Mr. Tibor
(uncredited) |
| Christopher Weigel | Penn Medical Doctor
(uncredited) |