| Nathan Fillion | Richard Castle |
| Stana Katic | Kate Beckett |
| Susan Sullivan | Martha Rodgers |
| Jon Huertas | Javier Esposito |
| Seamus Dever | Kevin Ryan |
| Tamala Jones | Lanie Parish
(credit only) |
| Molly C. Quinn | Alexis Castle |
| Penny Johnson Jerald | Captain Victoria Gates |
| Lisa Edelstein | Rachel McCord |
| Antonio Sabato Jr. | Ramon Russo |
| Arye Gross | M.E. Sidney Perlmutter |
| Joshua Bitton | Grant 'Sully' Sullivan |
| James Patrick Stuart | Ethan Wright |
| Emily Baldoni | Svetlana Renkov
(as Emily Foxler) |
| Alan Blumenfeld | Hank Harper |
| Ruth Williamson | Geraldine Powers |
| Jon Paul Burkhart | Potential Dewey |
| Jeff Grace | Charlie Reynolds |
| Nick Gracer | Vlad Bardinov |
| Kiyano La'vin | Construction Worker |
| Myko Olivier | Pi |
| JJ Snyder | Reporter
(as Jennifer Jean Snyder) |
| Mitchell Stanek | Russian Mob Operative
(uncredited) |
| Eric Womack | Russian Mob Operative
(uncredited) |