|Dr. Jonah Doyle|
|Occupation||General, Physician (United States Military)|
|Played By||Linden Banks|
Dr. Jonah Doyle is a former general in the US military that was in charge of the Levitas project.
LuthorCorp was the civilian contractor on the Levitas Project. The project's aim was to design a serum that would make anyone the ultimate interrogator. However, he dismantled the project because of increasing dangers to test subjects, causing LuthorCorp to lose millions. Dr. Doyle was dishonorably discharged from the military for his efforts.
When Chloe Sullivan was exposed to the serum, she began to exhibit dangerous physiological symptoms such as headaches and fainting spells. Her best friend Clark Kent discovered Doyle's involvement in the project and sought him out. Clark found Doyle living in Suicide Slums in a car garage. Doyle told Clark about his role in the project and informed Clark that Chloe would be dead in less than a day without an antidote. He then produced a sample, but warned Clark that it had never been tested, so he couldn't guarantee what would happen after its administration. However, his antidote proved to be effective and Chloe was restored to normal.