The Judge Advocate General's Corps of the United States Army, also known as the U.S. Army JAG Corps, is the legal arm of the United States Army. It is composed of Army officers who are also lawyers and who provide legal services to the Army at all levels of command, and also includes legal administrator warrant officers, paralegal noncommissioned officers and junior enlisted personnel, and civilian employees.

The Judge Advocate General of the United States Army (TJAG)—the commanding general of the Army JAG Corps—is a lieutenant general. All military officers are appointed by the U.S. president subject to the advice and consent of the Senate, but the Judge Advocate General is one of the few positions in the Army explicitly provided for by law in Title 10 of the United States Code, and requiring a distinct appointment. When officers who have already been appointed to another branch of the Army join the JAG Corps, rather than merely transferring branches, they are administratively dismissed and simultaneously recommissioned anew as judge advocates.