David D. McKiernan was a United States Army four-star general who served in Afghanistan as Commander, International Security Assistance Force (ISAF) from June 3, 2008 to June 15, 2009. He served concurrently as Commander, U.S. Forces Afghanistan (USFOR-A) from October 6, 2008 to June 15, 2009.

Prior to Afghanistan, McKiernan was Commanding General, U.S. Army, Europe and Seventh U.S. Army from December 14, 2005 to May 2, 2008. Before promotion to four-star rank, he served as Commanding General, Third U.S. Army and Coalition Forces Land Component Command (CFLCC) from 2002 to 2004, where he commanded all allied ground forces during the 2003 invasion of Iraq, and as Deputy Commanding General, U.S. Army Forces Command, the Army's largest major command, from 2004 to 2005.

On May 11, 2009, Defense Secretary Robert Gates asked for McKiernan's resignation from ISAF and USFOR-A. Gates said new leadership was needed as the administration of President Barack Obama launched a new strategy in the seven-year-old Afghanistan war. McKiernan was replaced by two generals, General Stanley A. McChrystal (Commander) and Lieutenant General David Rodriguez (Deputy Commander), ISAF and USFOR-A.