|Full Name||Frank London|
|Occupation||M.I.9 Spy Handler, Caretaker|
|School||Saint Hopes, Saint Hearts|
|Enemy||KORPS, SKUL, SKUM|
|First Episode||Art Attacks|
|Last Episode||The Last Stand|
|Portrayed By||Jonny Freeman|
He is an uncannily intelligent man who leads the M.I. High team. He poses as the school caretaker which is why most of the students and staff don't take him seriously and find it hard to believe he went to university. His storeroom is the secret entrance to the M.I.9 base, deep beneath the school. He has his own personal spy gadgets including a signalling device concealed within the handle of his broom, which he uses when in caretaker disguise to contact agents under his care.
He has formed many friendships with his teams, the most meaningful ones being with Oscar Cole, an orphan who looked up to Frank as a father figure, and Zoe; a clone who was trained by SKUL, she too looks up at Frank as a father figure and he is very sympathetic towards her.
Stella Knight used to be Frank's girlfriend ten years ago until she dumped him. In "The Fall of SKUL", it is shown that they are still close. In "Trojan KORPS" it is revealed that he used "L.O.V.3.L.Y.S.T.3.L.L.A" (lovely Stella) as his password in the bunker 10 years ago. Stella is still very protective of Frank. There can be a lot of tension between them and it is revealed that 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. In "The Final Endgame" when Frank is dying in the reactor core while trying to stop an overload, Stella goes in after him to help, knowing that she too would die. She helps him complete the code and then they sit down together as they are both dying. They end up fixing what had happened ten years ago and Stella realises that it wasn't his fault. 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."
Also, he has a fierce sense of right and wrong: In spite of his extreme hatred of SKUL and what they have taken from him, he still tenaciously believes that it is unfair for them to influence the General Election when the Grand Master attempts to become Prime Minister, on account of the fact that it is against M.I.9 regulations and violates the spirit of free elections.
- Frank is the second M.I. High spy handler. He is good with technology and creates almost half the gadgets the team uses.
- He is agent Stark's rival.
- In the episode, "Art Attacks", it is revealed that he used to train Rose.
- In "The Fall of SKUL" Frank London tells Kenneth Flatley that Zoe is his niece and her old school burned down.
- In the episode, "The Fall of SKUL", his relationship with Stella is revealed, it is further hinted throughout Series 6 and was further discussed in, "One Flew Over the Budgie's Cage".
- As shown in the episode, "One Flew Over the Budgie's Cage", he was awarded the M.I.9 medal for bravery.