| Carter Nash was a chemist in a police department who discovered a liquid which could turn him into Captain Nice, an odd sort of superhero: very shy and dominated by his mother. Captain Nice flew (he feared heights) in his tattered leotards, fighting bad guys because his mother told him to do so. |
| Name | Character | Episodes |
|---|---|---|
| William Daniels | Carter Nash | 15 |
| Sabrina Scharf | Miss Schneider | 15 |
| Liam Dunn | Mayor Finney | 15 |
| Ann Prentiss | Candy Kane | 15 |
| Alice Ghostley | Mrs. Nash | 15 |
| Byron Foulger | Mr. Nash | 15 |
| Bill Zuckert | Chief Segal | 15 |
| John Dehner | 2 | |
| John Fiedler | Gunnar | 1 |
| Victor French | 1 | |
| Charles Grodin | News Vendor | 1 |
| Bob Newhart | Lloyd Larchmont | 1 |
| Vic Tayback | 1 | |
| Charles Dierkop | Bank robber (uncredited) | 1 |
| Pat Harrington, Jr. | 1 | |
| Frank Maxwell | 1 | |
| Barbara Stuart | 1 | |
| Larry D. Mann | 1 | |
| Felice Orlandi | 1 | |
| Simon Oakland | 1 | |
| Edward Binns | 1 | |
| Madlyn Rhue | Amanda Woolf | 1 |
| Joseph Campanella | 1 | |
| Daniel J. Travanti | Lenny | 1 |
| Celeste Yarnall | 1 | |
| Jo Anne Worley | Rusty | 1 |
| Ross Hagen | Jake | 1 |
| Florence Halop | Mrs. Kowalski | 1 |
| Julie Parrish | 1 | |
| Margaret Teele | Babsy | 1 |
| Johnny Haymer | 1 | |
| Joe Flynn | 1 |