Stephen P. Hempstead (October 1, 1812–February 16, 1883) was the second governor of the U.S. state of Iowa. A Democrat, he served from 1850 to 1854.

Hempstead was born in New London, Connecticut. He moved to the Iowa territory, and was active in politics in the years leading up to Iowa's gaining statehood. Hempstead represented the northern parts of Iowa in the Territorial Legislature at Burlington, Iowa.

Hempstead represented Dubuque County in the Iowa constitutional convention in 1848. Hempstead was subsequently elected as governor in 1850. In 1851, he helped write the laws which would form the basis of the Iowa code.

After his term as governor was finished, Hempstead then was elected as a judge in Dubuque County. He held this position for 12 years, from 1855 to 1867. Hempstead died on February 16, 1883. He was then buried in Linwood Cemetery. In the late 1960s, the city of Dubuque, Iowa honored Hempstead by naming its new second public high school after him.