Ogden Livingston Mills (August 23, 1884–October 11, 1937) was an American businessman and politician.

The son of Ogden and Ruth T. (Livingston) Mills and grandson of Darius O. Mills, who bequeathed to his son a fortune in excess of $40 million amassed in banking, railroad and mining ventures on the Pacific Coast, Odgen Jr. was born in Newport, Rhode Island and attended the public schools. He graduated Harvard University in 1904 and Harvard Law School in 1907. He became a lawyer in New York in 1908.

He was a delegate to the Republican National Conventions in 1912, 1916, and 1920.

He served in the New York Senate from 1914 until 1917, when he resigned to enlist in the United States Army, and served with the rank of captain until the close of the First World War

He was president of the New York State Tax Association and a businessman until he was elected as a Republican to the 67th, 68th and 69th Congress from New York's 17th District, serving from 1921 to 1927. He married Mrs. Dorothy Randolph Fell in 1924.

He was appointed by President Calvin Coolidge Undersecretary of the Treasury to Secretary Andrew W. Mellon and served from 1927 until 1932 when he was appointed Secretary of the Treasury by Herbert Hoover upon Mellon's resignation to serve as U.S. Ambassador to the Court of St. James. Mills served until March 3, 1933.

After leaving the Treasury Department, Mills was highly critical of FDR's New Deal policies. He continued to be active in business, and published his views in two books, What of Tomorrow in 1935 and The Seventeen Million in 1937. The latter was his attempt to provide guidance for those who voted against the New Deal in 1936.

He was director of such large corporations as the Lackawanna Steel Company, the Atcheson, Topeka, and Santa Fe Railroad, Mergenthaler Linotype Company, the Shredded Wheat Company, et al.

He died in New York City and is interred in St. James Churchyard, Hyde Park, New York.