Mark Alexander Milley, born on June 20, 1958, in Winchester, Massachusetts, is a retired United States Army general who served as the 20th Chairman of the Joint Chiefs of Staff from October 1, 2019, to September 30, 2023. Prior to this role, he was the 39th Chief of Staff of the Army from August 14, 2015, to August 9, 2019. Throughout his military career, Milley held various command and staff positions across multiple divisions and special forces units.

Milley hails from a family with a strong military background. His father, Alexander Milley, served as a U.S. Navy corpsman during World War II, participating in significant battles such as Kwajalein, Saipan, Tinian, and Iwo Jima. His mother, Mary Elizabeth (née Murphy), was a Navy nurse who served with the WAVES during the same war. Raised in a Roman Catholic household, Milley attended a Catholic grammar school where he developed a passion for hockey. His academic and athletic prowess led him to Belmont Hill School and subsequently to Princeton University, where he played varsity ice hockey.

At Princeton, Milley joined the Reserve Officers' Training Corps (ROTC) and graduated in 1980 with a Bachelor of Arts in politics. He furthered his education by earning a Master of International Affairs from Columbia University's School of International and Public Affairs and a Master of Arts in national security and strategic studies from the Naval War College. Additionally, he attended the MIT Center for International Studies Seminar XXI National Security Studies Program.

Commissioned as an armor officer in 1980, Milley's early military career included participation in operations such as Operation Just Cause, Operation Uphold Democracy, Operation Joint Endeavor, the Iraq War, and the War in Afghanistan. He commanded units including the 2nd Brigade Combat Team of the 10th Mountain Division and the 10th Mountain Division itself. He also led the International Security Assistance Force Joint Command and III Corps. In August 2015, Milley became the Chief of Staff of the Army, and in October 2019, he was appointed Chairman of the Joint Chiefs of Staff by President Donald Trump, becoming the principal military advisor to the President, Secretary of Defense, and the National Security Council.

After retiring from active duty in September 2023, Milley transitioned to academia and the private sector. In February 2024, he joined the faculties of Georgetown University and Princeton University. At Georgetown, he served as a distinguished fellow in residence with the Security Studies Program in the School of Foreign Service. At Princeton's School of Public and International Affairs, he was appointed the Charles and Marie Robertson visiting professor and lecturer. Concurrently, Milley became a senior adviser to JPMorgan Chase and joined the Harry Walker Agency as a speaker.

On a personal note, Milley married Hollyanne Haas in May 1985, and they have two children. Hollyanne is a nurse with extensive experience in critical care and cardiac nursing. Notably, during the 2020 Veterans Day ceremony at Arlington National Cemetery, she administered life-saving CPR to a veteran who had collapsed.

Throughout his distinguished career, Milley received numerous awards, including the Defense Distinguished Service Medal, Army Distinguished Service Medal, Defense Superior Service Medal, Legion of Merit, and the Bronze Star Medal. His contributions to military strategy and leadership have been widely recognized, and he continues to influence national security discussions through his academic and advisory roles.