Citizen One is a character that appears in the Sonic the Comic series published by Fleetway Editions. It is a computer program created by Dr. Ivo Robotnik. Citizen One is an enormous solid light hologram, able to construct anything out of its pixels.
Shortly after being created, Doctor Robotnik abandoned Citizen One because it desired to create a happy Zone for its residents. Months later, Citizen One became lonely and wished for company. It created a holographic Zone called Perfection, then abducted several Mobians into living there, brainwashing them into following Citizen One's strict rules and turning them into Citizens Two to Six. When Sonic came to investigate the missing Mobians, Citizen One kidnapped him and tried to brainwash him too, but Sonic resisted the brainwashing and exposed Citizen One as a computer program.
Sonic explained that Citizen One did not need to brainwash people, and that it would have lots of residents if it created a Zone people would willingly visit. Citizen One then dissolved Perfection and created a giant carnival, which was soon full of visitors.