The unanimous decision is a dramatic setback for I. Lewis "Scotter" Libby's legal case and puts pressure on President George W. Bush, who has been sidestepping calls by Libby's allies to pardon the former White House aide.
Libby faces 2 1/2 years in prison for lying and obstructing the investigation into the 2003 leak of CIA operative Valerie Plame's identity. Her husband was an outspoken Iraq war critic.
The former chief of staff to Cheney, Libby is the highest-ranking White House official ordered to prison since the Iran-Contra arms scandal in the 1980.
He had hoped the U.S. Court of Appeals for the District of Columbia Circuit would put that sentence on hold because he believes he has a good chance of overturning the conviction on appeal. The court unanimously rejected the request.
The U.S. Bureau of Prisons has not assigned Libby a prison yet or given him a date to surrender but last week designated him federal inmate No. 28301-016.