The nine-member panel will be co-chaired by former U.S. Sen. Chuck Robb, D-Va.; and retired Judge Laurence Silberman. Bush listed seven members of the commission -- including Sen. John McCain, R-Ariz. -- leaving two slots left to be filled.
The commission is to issue a report by March 31, 2005.
Bush's actions came on the heels of congressional testimony by former chief U.S. weapons inspector David Kay that Iraq had no weapons of mass destruction immediately before last March's invasion. Secretary of State Colin Powell has said he does not know whether he would have recommended an invasion had he known Iraq did not possess banned weapons.
Bush on Thursday defended his decision to go to war, telling supporters in Charleston, S.C., "Knowing what I knew then, and knowing what I know today, America did the right thing in Iraq."