James Russell "Jimmy" Murphy was an American attorney, soldier, and intelligence officer who served as the chief of the X-2 Counterintelligence Branch of the Office of Strategic Services (OSS) during World War II. From 1943 to 1946, held the position of chief of counterintelligence at both the OSS, and later at the Strategic Services Unit (SSU). Though primarily stationed in Washington, D.C., during the war, he made frequent trips to the European and African Theatres, including London and Morocco.

Murphy played a critical role in wartime counterintelligence efforts, reportedly helping to identify approximately 3,000 foreign agents, many of whom were turned into double agents used to transmit misleading information to Axis powers. He also contributed to the development of effective, non-coercive interrogation methods that aided military intelligence gathering. He would also regularly visit his X-2 agents on the front line in order to offer moral support and provide courage.

William Donovan wrote:

"A firm agreement with the British was made in March and April 1943, and carried out on a basis of loyal cooperation and full interchange of pertinent information throughout the war. Mr. Murphy was not, however, content to remain in tutelage of the old established foreign agencies. His constant aim was to develop American counter-espionage to the point of being an equal partner with its allies."

James Russell Murphy was born in Piedmont, Missouri, in 1904. He moved to Washington, D.C., in the 1920s after winning a national typewriting competition, which awarded him a federal government job. He began his career as a typist and during this time became acquainted with William J. "Wild Bill" Donovan, the decorated Medal of Honor winner and World War I veteran. While working in Donovan's law office at the United States Department of Justice, Murphy became one of Donovan's main protégés, learning all he could from the senior lawyer while practicing for entry into law school.

While employed in Washington, Murphy enrolled in George Washington University Law School, attending classes at night. He earned his law degree in 1931 and subsequently practiced law privately in the city for the following decade.

In 1941, Murphy joined Wild Bill Donovan in establishing the Office of the Coordinator of Information (COI), the precursor to the Office of Strategic Services (OSS). As a talented typist, he was indespensible to Donovan, and afterwards Murphy served briefly as the executive assistant to Donovan.

Murphy and Donovan were close friends, trusted confidants, and especially drinking buddies. At one point during his tenure as director of the OSS, Donovan frustrated by ongoing inter-agency conflicts, prepared a resignation letter. He entrusted the letter to Murphy, instructing him to deliver it to the White House the following morning. However, by the next day, Donovan had reconsidered. When he asked Murphy if he still had the letter, Murphy quietly retrieved it from his coat pocket and returned it without comment.