| Nathan Fillion | Richard Castle |
| Stana Katic | Kate Beckett |
| Susan Sullivan | Martha Rodgers |
| Ruben Santiago-Hudson | Captain Roy Montgomery |
| Molly C. Quinn | Alexis Castle
(as Molly Quinn) |
| Jon Huertas | Javier Esposito |
| Tamala Jones | Lanie Parish |
| Seamus Dever | Kevin Ryan |
| Andrew Leeds | Adam Murphy
(as Andrew Harrison Leeds) |
| Ian Nelson | Troy Kenworth |
| Ken Baumann | Ashley |
| Victor Webster | Josh Davidson |
| Muse Watson | Ivan Podofski |
| Thomas Kopache | Abe Sandrich |
| Jim Piddock | Lord Henry |
| Ramon De Ocampo | Owen Peterson |
| Randal Reeder | Roland D'Andre |
| Eden Riegel | Rachel Goldstein |
| Jen Lilley | Julia Foster |
| Eugene Shaw | Joe |
| Billy Atchison | Daniel Goldstein
(uncredited) |
| Dawnielle Banks | Steampunk Woman
(uncredited) |
| Bryan Forrest | Steampunk Gentleman
(uncredited) |
| Sarah Hunter | Steampunk Club Goer
(uncredited) |
| Robin Lynn | Steampunk Courtesian
(uncredited) |
| Brettney Perr | Steampunk Pirate
(uncredited) |
| Chris Sanders | Steampunk Gentleman
(uncredited) |
| Ciel Turich | Bike Messenger
(uncredited) |
| Thomas Willeford | Background
(uncredited) |