Rush Clark (October 1, 1834 – April 29, 1879) was a nineteenth-century politician and lawyer from Iowa, who died on the floor of Congress in 1879.

He was a member of the Iowa House of Representatives from 1860 to 1864, serving as Speaker of the House in 1863 and 1864, served on the staff of Governor Samuel J. Kirkwood in 1861 and 1862 and aided in the organization of volunteer regiments from Iowa during the Civil War.

However, on April 29, 1879, near the beginning of the first session of his second term, he died suddenly on the floor of the House, reportedly suffering an attack of meningitis.

A previous son, Eugene Rush Clark, had died during birth in 1865.

Clark married again in a few years, and to this union, several more children were born, of which two lived.