James Wilson McDill (March 4, 1834 – February 28, 1894) was an American lawyer, state-court judge, Republican United States Representative and Senator from Iowa, state railroad commissioner, and member of the Interstate Commerce Commission.

He was a clerk in the office of the Third Auditor of the Treasury in Washington, D.C., from 1862 to 1865, when he resigned and returned to Iowa.

After his term ended, he was again appointed Railroad Commissioner for three years beginning in April 1884.

[2] In 1892, he was appointed by President Benjamin Harrison a member of the Interstate Commerce Commission and served until his death in Creston, Iowa, in 1894.

James W. McDill Papers are housed at University of Iowa Libraries Special Collections & Archives