Series episode
| Donnie Wahlberg | ... | Danny Reagan |
| Bridget Moynahan | ... | Erin Reagan-Boyle |
| Will Estes | ... | Jamie Reagan |
| Len Cariou | ... | Henry Reagan |
| Tom Selleck | ... | Frank Reagan |
| Bobby Cannavale | ... | Charles Rossellini |
| Amy Carlson | ... | Linda Reagan |
| Nicholas Turturro | ... | Sgt. Anthony Renzulli |
| Olek Krupa | ... | Grushenko |
| Lola Glaudini | ... | Anna |
| Pawel Szajda | ... | Sergei |
| Sami Gayle | ... | Nicky Reagan-Boyle |
| Luke Robertson | ... | Boris |
| Jimmy Palumbo | ... | Chief Winston |
| Ralph Byers | ... | St. Clair |
| Josh Casaubon | ... | Joshua Saunders |
| Dylan Chalfy | ... | Firestone |
| Jennifer Esposito | ... | Jackie Curatola |
| Tony Terraciano | ... | Jack Reagan |
| Andrew Terraciano | ... | Sean Reagan |
| Abigail Hawk | ... | Detective Melissa Baker |
| Sofia Sokolov | ... | Sofia |
| Topher Mikels | ... | Mischa |
| Anna Eilinsfeld | ... | Svetlana Bayul |
| Vladimir Bibic | ... | Yuri |
| Dieter Riesle | ... | Vladmir Sarbonis |
| Mahira Kakkar | ... | Dr. Gupta |
| Larisa Polonsky | ... | Chelsea Cole |
| Bruce Altman | ... | The Mayor |
| Derek Hedlund | ... | Officer Wilson |
| Mat Hostetler | ... | Handler |
| Jason Jurman | ... | Jeffrey |
| Addison LeMay | ... | Boris the Bodyguard |
| Scott Churchson | ... | Russian Mobster |
| Stephen Gyllenhaal | ... | Direction |
| Mark Rosner | ... | Script |