Reilly, a native of Winnetka, Illinois, and a graduate of New Trier High School's West Campus, comes from a family with more than a century of service in the U.S. Military. Commissioned in 1975 through the Naval Reserve Officer Training Corps, he first served aboard the as Electronic Material Officer, Combat Information Center Officer and Damage Control Assistant. His other shipboard tours included commissioning the as its first Operations Officer; Engineering Officer aboard the ; Executive Officer of the Spruance-class destroyer ; and as Commanding Officer of the . Reilly's additional operational tours at sea included duties as Flag Secretary, Cruiser Destroyer Group One, where he participated in the western Pacific and Southwest Asia deployments of the and Battleship Battle Groups, and the Carrier Battle Groups; and command of Destroyer Squadron Fifty, homeported in the Kingdom of Bahrain. He also commanded Cruiser Destroyer Group Two and the Carrier Strike Group. Ashore, Reilly served as Operations Readiness Assessment Officer, Commander, U.S. Pacific Fleet staff in Pearl Harbor, Hawaii; Surface Warfare and Weapons Procurement Analyst, Program Resource Appraisal Division, Office of the Chief of Naval Operations; Surface Warfare Junior Officer Assignment Branch Head, Bureau of Naval Personnel; Joint Operations Division Pacific Command Division Chief, Joint Staff ; Director, Environmental Readiness, Chief of Naval Operations ; and as Deputy Assistant Chief of Naval Operations for Information Technology and Department of the Navy Deputy Chief Information Officer. Reilly assumed command of the Military Sealift Command in March 2006. During his tenure MSC returned nearly $1 billion to the Navy’s budget through improved business practices; won awards for contracting excellence, competitive procurement, small business, safety and environmental responsibility; improved energy efficiencies; placed additional helicopter detachments aboard U.S. navy fleet logistics ships, saving $700 million in cost avoidance over 20 years; deployed the U.S. Navy's two hospital ships and on five humanitarian and civic assistance missions treating more than 370,000 patients in 25 countries; evacuated 6,700 U.S. citizens from Beirut to safety in 2006; and delivered of combat equipment and supplies and of fuel to U.S. and coalition forces ashore in Iraq and Afghanistan with a 98 percent on-time delivery record. Reilly earned a Bachelor of Arts degree in Political Science from the University of Washington, and a Master's in Public Administration from the George Washington University. He is also a 1993 graduate of the Industrial College of the Armed Forces.