Mark Hamilton Landes is a career officer in the United States Army who has commanded First United States Army since September 2024. A 1990 graduate of the United States Military Academy, and a veteran of the Iraq War, War in Afghanistan, and Operation Inherent Resolve, he was promoted to major general in 2021. Landes' commands included 2nd Battalion, 23rd Infantry Regiment, 3rd Brigade, 1st Armored Division, Security Force Assistance Command, and First Army Division East. In March 2024, Landes was appointed special assistant to the U.S. Army Forces Command commander. In June 2024, he was nominated for promotion to lieutenant general and assignment as commander of First United States Army. His promotion and assignment were confirmed in August 2024.