Robert Clymer Hendrickson (August 12, 1898 – December 7, 1964) was an American attorney, politician, and diplomat who served as a United States senator from New Jersey.
After graduating from law school, Hendrickson was admitted to the New Jersey bar, commencing practice in Woodbury. He held the office of county supervisor from 1929 to 1934, and was city solicitor of Woodbury in 1931. He was a member of the New Jersey Senate from 1934 to 1940, serving as president of the senate in 1939; he was an unsuccessful Republican nominee for governor in 1940. He served as state treasurer from 1942 to 1949 and was a member of the board of managers of the Council of State Governments in 1940, and was its chairman in 1941. He was vice chairman of the Commission on the Delaware River Basin from 1936 to 1951. He served on the New Jersey Constitutional Revision Commission.
During the Second World War he rejoined the Army in 1943, was commissioned a major, served with the American Military Government in the Mediterranean Theater of Operations, and was subsequently promoted to lieutenant colonel in 1944, being separated from the service in 1946. As a senior legal officer in the U.S. Army in North Africa, Italy, and Austria, he worked on the re-establishment of civil rights and local courts, the implementation of de-nazification programs, and the care of displaced persons. He was called back into active duty for the Korean War in 1951. In 1948, he was elected as a Republican to the U.S. Senate, and served from January 3, 1949, to January 3, 1955; he was not a candidate for renomination in 1954. President Dwight Eisenhower appointed Hendrickson to the post of United States ambassador to New Zealand, which he held from February 16, 1955, to November 20, 1956.
