| The Trials of O'Brien is a 1965 television series starring Peter Falk as a sordid Shakespeare-quoting lawyer and featuring Elaine Stritch as his secretary and Joanna Barnes as his ex-wife. The series ran for only 22 episodes. Among its guest stars: Milton Berle, Robert Blake, David Carradine, Faye Dunaway, Britt Ekland, Tammy Grimes, Buddy Hackett, Gene Hackman, Frank Langella, Angela Lansbury, Cloris Leachman, Roger Moore, Rita Moreno, Estelle Parsons, Joanna Pettet, Brock Peters, Tony Roberts and Martin Sheen. Falk often said that he actually liked this financially unsuccessful series much better than his later smash-hit Columbo. |
| Name | Character | Episodes |
|---|---|---|
| Peter Falk | Daniel O'Brien | 22 |
| Elaine Stritch | Miss G | 22 |
| Joanna Barnes | Katie O'Brien | 22 |
| David Burns | The Great McGonigle | 22 |
| Dolph Sweet | Sgt. Garrison | 8 |
| Ilka Chase | Margaret | 4 |
| George Coulouris | 2 | |
| Barnard Hughes | 2 | |
| Gene Hackman | Roger Nathan | 1 |
| Will Geer | Judge Lindemann | 1 |
| Robert Walker Jr. | Arthur Barry (as Robert Walker) | 1 |
| David Doyle | Murray | 1 |
| Reni Santoni | Leonard | 1 |
| Alejandro Rey | Francisco Perez | 1 |
| Nan Martin | 1 | |
| Alice Ghostley | 1 | |
| Estelle Parsons | 1 | |
| Brock Peters | Isadore Jaconey | 1 |
| Conrad Bain | 1 | |
| Diane Kagan | Sister Aimee | 1 |
| Edgar Stehli | Judge Altman | 1 |
| Edgar Stehli | Judge | 1 |
| Edgar Stehli | Judge Prescott | 1 |
| Tammy Grimes | Mother Superior | 1 |
| Valerie Allen | Roseanne | 1 |
| Marc Connelly | 1 |