Edgar Erastus Clark (February 18, 1856 – December 1, 1930) was an American attorney, railway union official, and government employee.

The chief executive of the Order of Railway Conductors for more than 15 years, Clark served on the Interstate Commerce Commission from 1906 to 1921, and was its chairman from 1913 to 1914 and 1918 to 1921.

[3] After leaving school, Clark headed west in search of work and adventure, landing in Austin, Minnesota, where he found a job as a brakeman on the Burlington, Cedar Rapids, and Northern Railway.

[5] Clark involved himself in lobbying, and received credit for the 1898 enactment of a Mediation and Arbitration Act, which provided for a permanent board to settle disputes between railways and their employees.

[4] In 1906, Roosevelt nominated Clark to one of two new seats on the Interstate Commerce Commission created by the Hepburn Act.

[4] Nonetheless, Clark was immediately reappointed as Commissioner by the new President, Woodrow Wilson, on March 5, 1913, and was confirmed by the Senate the same day.