James Northey Miller Jr. (born August 15, 1959) is the Johns Hopkins Applied Physics Laboratory's Assistant Director for Policy and Analysis and also serves on the National Security Council staff as U.S. Coordinator for the Australia-United Kingdom-United States (AUKUS) security agreement. He previously served as the Under Secretary of Defense for Policy from February 18, 2012 until January 8, 2014 and as Deputy Under Secretary of Defense from April 2009 to February 2012.