| Actor | Character | Firearm | Notes |
|---|---|---|---|
| Steve Zahn | Jack Monk, Jr. | Beretta 92FS | "Mr. Monk's Other Brother"; appears as "Lane & Westen" 9mm |
| Titus Welliver | Daniel Reese | Ruger Mini-14 | "Mr. Monk's Other Brother" (S7E10) |
| Traylor Howard | Natalie Teeger | Walther PPK/S | "Mr. Monk on Wheels" (S7E11) |
| William Atherton | Lt. Commander Nathan Whitaker | Walther P38 | "Mr. Monk is Underwater" |