He graduated from Brown University in 1908 and Harvard University School of Law in 1911.
John Joseph O'Connor (November 23, 1885 – January 26, 1960) was an American politician from New York. He was elected as a Democrat to the 68th United States Congress to fill the vacancy caused by the death of W. Bourke Cockran, and was re-elected to the 69th, 70th, 71st, 72nd, 73rd, 74th and 75th United States Congresses, holding office from November 6, 1923, to January 3, 1939. He was one of the few Democrats targeted in the 1938 primaries by Franklin D. Roosevelt to be defeated.
He was a delegate at large to the 1936 Democratic National Convention. He died in Washington, D.C. He was Chairman of the House Rules Committee between 1935 to 1939.
He was interred at Gate of Heaven Cemetery in Silver Spring, Maryland.
He was a member of the New York State Assembly (New York Co, 12th D) in 1921, 1922 and 1923.