Oscar was the son of Orville M. Hundley and the former Mary Holding. He attended preparatory school at the Phillips Exeter Academy of Exeter, New Hampshire, then spent two years at Marietta College in Marietta, Ohio before entering law school at Vanderbilt University in Nashville, Tennessee. He completed his law degree in 1877 and worked in private practice in Huntsville. He was elected to serve as Huntsville's city attorney in 1882 and re-elected in 1883, writing its revised Code of Ordinances. After that he was employed as division counsel to the Nashville, Chattanooga & St Louis Railway from 1884 to 1907.
In 1886 Hundley was elected to a four year term on the Alabama House of Representatives. In 1890 he was elected to the State Senate, serving until 1898. In the 1896 general election Hundley ran unsuccessfully to represent the 8th Congressional District of Alabama in the U.S. House of Representatives.
After the death of his first wife, the former Anna E. Thomas, Hundley married Bossie O'Brien, daughter of his former colleague in the House of Representatives, Frank O'Brien. They exchanged vows on June 24, 1897.
In 1904 Hundley traveled to as a delegate to the Republican National Convention in Chicago, Illinois. Two years later he was appointed an Assistant United States Attorney for the Northern District of Alabama. On April 9, 1907 President Theodore Roosevelt used a recess appointment to elevate him to a newly-created place on the bench of the United States District Court for the Northern District of Alabama. The Senate, citing the "unfit receivers" he had appointed to oversee the liquidation of the Southern Steel Company, refused to confirm the appointment when they returned to session, and he lost the seat on May 30, 1908.
Roosevelt used another recess appointment to return him to the court, with the same result, his term expiring on March 3, 1909. Three days later, President William Taft used a recess appointment to put Hundley back onto the bench, but this time he resigned, effective May 25, before his formal nomination was submitted to the Senate.
Beginning in 1913, Hundley served as president and general counsel of the Sun Life Insurance Company. Along with his wife, an active suffragist, Hundley traveled to Chicago, Illinois to attend the 1916 Republican National Convention.
|Judge of the United States District Court for the Northern District of Alabama