William Wright Arnold (October 14, 1877 – November 23, 1957) was an American politician and jurist, serving as a U.S. representative from Illinois and a judge of the United States Tax Court.

He was admitted to the bar the same year and commenced the practice of law in Robinson, Illinois.

He was continuously engaged in the practice of his chosen profession until elected to Congress.

Arnold was elected as a Democrat to the Sixty-eighth and to the six succeeding Congresses and served from March 4, 1923, until his resignation, effective September 16, 1935, having been appointed July 29, 1935, a member of the United States Board of Tax Appeals (which became the United States Tax Court during his service).

This article incorporates public domain material from the Biographical Directory of the United States Congress