Robert Porter Patterson Sr. (February 12, 1891 – January 22, 1952) was an American judge who served as Under Secretary of War under President Franklin D. Roosevelt and U.S. Secretary of War under President Harry S. Truman. He was a US circuit judge of the United States Court of Appeals for the Second Circuit after he had been a district judge of the United States District Court for the Southern District of New York.

Robert Porter Patterson Sr.
Second Circuit Court of Appeals
Born 1891 in Glens Falls, NY
Died 1952 in Elizabeth, NJ
FJC ID: 1849
- Gender
- Male
- Race
- White
Prior employment
- Private practice, New York City1915–1916, 1919–1930, 1947–1952
- Secretary of War1945–1947
- Undersecretary of war1940–1945
- Assistant secretary of war1940
U.S. Army1917–1919- New York Army National Guard1916–1917
Appointments
1939–1940 · Appointed by Franklin D. Roosevelt (Democratic)Term ended: Resignation
1930–1939 · Appointed by Herbert Hoover (Republican)Term ended: Appointment to Another Judicial Position
Education
LL.B. · 1915- Union CollegeA.B. · 1912