- Unnamed agent who allegedly employs plastic surgery to impersonate Hillary Gainsborough, a special weapons instructor at the CONTROL Training School [Episode #3: "School Days"].
- Alma Sutton, lab assistant [Episode #7: "KAOS in CONTROL"].
- Agent Kirsch, aka KAOS agent Y-11 [Episode #31: "Anatomy of a Lover"].
- Yohan, member of the League of Impostors who is a physical duplicate of Maxwell Smart [Episode #63: "The Spy Who Met Himself"].
- Another member of the League of Impostors who is a duplicate of the Chief [Episode #63: "The Spy Who Met Himself"].
- Commander Hathaway, head of British CONTROL/KAOS double agent; indeed, triple agent, as he is also head of the Scorpion Gang [Episode #70: "That Old Gang of Mine"].
- Van Cleef, Hathaway's assistant [Episode #70: "That Old Gang of Mine"].
- The Chameleon, disguise expert who variously poses as Larabee, Admiral Hargrade and Agent 99 [Episode #94: "The Return of the Ancient Mariner"].
- Kendall, KAOS double agent [Episodes 111 & 112: "The Not-So-Great Escape, Parts 1 & 2"].
In addition, a KAOS clone takes the place of the Chief of PITS for a time [Movie: "The Nude Bomb"] and Major Waterhouse of the United States Intelligence Agency is also a KAOS plant [TV Movie: "Get Smart, Again!"].