|Portrayed by John Prosky|
|Episode of Death:||Allegiance|
|Cause of Death:||Shot by Pascal LeMarchal|
|Hair color:||White (balding)|
Oscar Chapman was a reporter that went into hiding after the death of Trevor Mathis. He was killed by Pascal LeMarchal.
Shortly after Oscar Chapman has just moved London, he was contacted by Trevor Mathis, who wanted to tell the world that he unknowingly planted the bomb on Flight 197. Oscar gave the story to Pascal, and soon realized he had made a mistake. Trevor was murdered by Pascal soon after, and Oscar went into hiding.
In "Allegiance", Aiden Mathis, Trevor's son, and Nolan Ross tracked Oscar down while he was disguised as a woman. Oscar told Aiden the whole story regarding what happened with his father. Aiden had believed Trevor committed suicide because he was scared of facing punishment for his involvement. Nolan and Aiden asked Oscar to come forward, and he agreed. Oscar returned to his apartment after getting groceries, and found Pascal (who had been tipped off by Conrad Grayson), waiting for him. Pascal told Oscar that his problem was that he was too good of a reporter and then he shot Oscar, killing him.