Cartoon Network/Odd Squad

Agent Olive - Numbuh 3 (Codename Kids Next Door)

Agent Otto - Numbuh 4 (Codename Kids Next Door)

Agent Oscar - Dexter (Dexter's Laboratory)

Ms. O - Blossom (The Powerpuff Girls)

Mr. O - Grim (The Grim Adventures of Billy and Mandy)

Agent Olympia - Eileen (Regular Show)

Agent Otis - Rigby (Regular Show)

Agent Oona - Dee Dee (Dexter's Laboratory)

Agent Ocean - Clarence

Coach O - Numbuh 1 (Codename Kids Next Door)

Delivery Debbie - Nicole Watterson (The Amazing World of Gumball)

Delivery Doug - Richard Watterson (The Amazing World of Gumball)

Agent Orchid - Mandy (The Grim Adventures of Billy and Mandy)

Agent Ohlm - Billy (The Grim Adventures of Billy and Mandy)

Agent Octavia - Bubbles (The Powerpuff Girls)

Agent Oz - High Five Ghost (Regular Show)

Agent Oren - Tobias (The Amazing World of Gumball)

Agent Olaf - Banana Joe (The Amazing World of Gumball)

Odd Todd - Ice King (Adventure Time)

Shapeshifter - Ms. Simian (The Amazing World of Gumball)

Evil Teddy - Lee Kanker (Ed, Edd n Eddy)

Noisemaker - Kevin (Ed, Edd n Eddy)

Agent Oksana - Sarah (Ed, Edd n Eddy)

Coach Roberts - Benson (Regular Show)

Mayor Macklemore - Principal Brown (The Amazing World of Gumball)

Odenbacker - Skips (Regular Show)

O'Malley - Gil Nexdor (Johnny Test)

O'Brian - Eustace Bagge (Courage the Cowardly Dog)

O'Duffy - Mac (Foster's Home for Imaginary Friends)

Ori - Johnny Test

Oakley - Edd (Ed, Edd n Eddy)

Ophelia - Nazz (Ed, Edd n Eddy)