The court's action follows its April 2 decision not to step into related aspects of the legal battle regarding other Guantanamo Bay detainees.
In June, Hamdan won a landmark US Supreme Court ruling which led to a repudiation of the Bush administration.
Illegal system
The court had found the initial military tribunal system created to try terrorism suspects being held at Guantanamo Bay in Cuba to be illegal.
The ruling prompted George Bush, the US president, to seek congressional approval last year for tough interrogation and prosecution of terrorism suspects under a new military tribunal system.
The new law also took away the right of the prisoners to challenge their confinement before US federal judges.
The Supreme Court in early April rejected, for now, appeals by two different groups of Guantanamo prisoners.
Their challenge to the law was similar to the one brought by lawyers for Hamdan and Khadr.
There are about 385 detainees still at Guantanamo.
The first prisoners arrived more than five years ago after the US began what Bush called the "war on terror" in response to the September 11, 2001 attacks in the US.