|Full Name||Stella Knight|
|Eye Color||Dark Blue|
|Occupation||M.I.9 Chief Agent Officer|
|First Episode||The Fall of SKUL|
|Last Episode||The Last Stand|
|Portrayed By||Rebecca Ray Palmer|
She can be strict, but cares for the agents and doesn't want them to get hurt. If a mission goes wrong or something happens to the MI High team then she usually holds herself responsible, showing her more maternal side towards them. She also follows protocol no matter what; in the episode, "Trojan KORPS", she arrested Frank for being a traitor, even though her feelings said otherwise, because the evidence pointed to him.
She used to be Frank's girlfriend 10 years ago until she dumped him. In "The Fall of SKUL", it is shown that they are still close although tensions arise between them during the course of the series. It is revealed that the the source of this conflict is when Frank led the final assault on the KORPS base. The M.I.9 team suffered terrible losses and Stella blamed Frank for the disaster. She realizes it wasn't Frank's fault and in, "The Final Endgame", she risks her life to help him. Then they both kiss just before almost dying. After they are saved Stella asks if they can forget about it to which Frank replies with "No, I don't think we can."
She was removed from command and arrested in "The League of Mata Hari".
In "We Need to Talk About KORTEX" she is saved from prison by Frank, Keri and Dan then helps them take down KORPS. It is revealed that she was framed by Hamish Campbell and Mike Stern who were working for KORPS.
It is unknown whether she was reinstated after "We Need to Talk About KORTEX".
- Rebecca Palmer, who plays Stella, also plays Carla Terrini in "The Fugitive".
- "Free Runner" is her only appearance at Saint Hearts using a cover story for an "above ground" M.I.9 annual assessment.
- "The Fall of SKUL"
- "Trojan KORPS"
- "The Face Of Revenge"
- "Mission: Incredible"
- "The Hive"
- "Old School"
- "The Germinator"
- "One Flew Over the Budgie's Cage"
- "Prison Break"
- "The Final Endgame"
- "The Man Who Drew Tomorrow"
- "Revenge is Sweet"
- "The Shadow Games"
- "Return of the Dark Wizard"
- "Free Runner"
- "The League of Mata Hari"
- "We Need to Talk About KORTEX"
- "The Last Stand"