Private First Class O'Kelley was a member of Company G, 3rd Battalion, 5th Marines, 1st Marine Division. He was Killed in Action while fighting the enemy on Pork Chop Hill, Korea on 19 May 1951.

For his leadership and valor, Private O'Kelley was awarded the Bronze Star Medal, the Purple Heart, the Combat Action Ribbon, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.