Howell was born on September 21, 1863, in Atlanta. During the American Civil War his mother was in South Carolina while his father, Captain Evan Howell, served in the infantry and commanded a Confederate artillery battery.
Clark Howell attended the University of Georgia (UGA) in Athens where he was a member of the Phi Kappa Literary Society as well as an early member of the Gamma chapter of the Kappa Alpha Order, and graduated with an A.B. degree in 1883. Directly after he moved to New York City and began working as a reporter for the New York Times then worked as the night telegraph editor of the Philadelphia Press.
In 1880 he returned to Atlanta and worked as a reporter at the Atlanta Constitution where his father was editor-in-chief and a principal stock holder. After managing editor Henry W. Grady died in 1889, the younger Howell took over that position. He eventually succeeded his father as editor-in-chief in 1897 upon the elder Howell's retirement. That year he was elected to the Fulton County Board of Commissioners and served for one year. In 1901, Clark Howell purchased controlling shares in the Constitution to become its new owner.
Starting in 1886, Howell was elected to three terms in the Georgia House of Representatives and served as Speaker for one term. In 1900, he was elected one of the original directors of the Associated Press, a position he maintained the rest of his life. Also in 1900 he was elected to the Georgia Senate where he served consecutive two-years terms and was the President of that body during the latter term. Following that he was defeated in the contentious 1906 Democratic Georgia gubernatorial race won by Hoke Smith, owner of the rival Atlanta Journal newspaper.
Even though Howell was a lifelong Democrat, President Warren G. Harding placed him on a special mining commission in 1922 and ten years later President Hoover appointed him to a national transportation commission.
The Constitution won the 1931 Pulitzer Prize for Howell's series exposing the Atlanta graft ring which led to six indictments and the downfall of Mayor I. N. Ragsdale's political career. In 1934, President Roosevelt named him to chair the Federal Aviation Commission in the wake of the Air Mail scandal and appointed him chairman of a commission to study aviation in foreign countries. The French government made him a Chevalier of the Legion of Honor in 1935.
Clark Howell founded the radio station WGST (GST for Georgia School of Technology) as a gift to the Georgia Institute of Technology in 1922. Operating as a commercial station with educational opportunities for students, the radio station was officially owned by the Board of Regents. After several lawsuits, the station was sold to a private corporation in 1974. The school reacquired a radio station, now known as WREK. A freshman residence hall at Georgia Tech, Howell Hall, as well as an academic building at his alma mater, Clark Howell Hall, are named in his honor.
When he died he was the president and editor of the Atlanta Constitution and a director of the Associated Press.
- Reed, Thomas Walter. "Chapter IX: The Administration of Chancellor Patrick H. Mell". History of the University of Georgia. Athens, Georgia: University of Georgia Online Archives. pp. pp. 1176–1178. Retrieved 2007-01-18.
- Perry, Chuck (January 1, 2004). "Atlanta Journal-Constitution". New Georgia Encyclopedia. Retrieved 2007-01-18.
- Associated Press, November 14, 1936.
- Brittain, Marion L. (1948). The Story of Georgia Tech. Chapel Hill, NC: University of North Carolina Press.