| Actor | Character | Firearm | Notes |
|---|---|---|---|
| Andy Mackenzie | Drug Dealer | Glock 17 | "Mr. Monk Is Up All Night" (S6E09) |
| Scott Glenn | Sheriff John Rollins | Beretta 92FS | Under fictional name "Lane & Westen" / "Mr. Monk Is On The Run, Part I" (S6E16) |
| Tony Shalhoub | Adrian Monk | Smith & Wesson Model 36 | Pearl grips / "Mr. Monk and the Man Who Shot Santa Claus" |