William H. Parker
Frontispiece of 1909's William H. Parker, a Representative from South Dakota
Member of the U.S. House of Representatives from South Dakota's at-large district
In office March 4, 1907 – June 26, 1908
Preceded by	Eben Martin
Succeeded by	Eben Martin
Personal details
Born	(1847-05-05)May 5, 1847 Keene, New Hampshire, U.S.
Died	June 26, 1908(1908-06-26) (aged 61) Deadwood, South Dakota, U.S.
Resting place	Arlington National Cemetery
Political party	Republican
Spouse	Clara E. Thomas ​ (m. 1867)​
Children	2
Relatives	William H. Parker (Grandson)
Education	Columbian College (LL.B., 1868)
Occupation	Attorney
Military service
Allegiance	United States (Union)
Branch/service	Union Army
Years of service	1861–1866
Rank	Second Lieutenant (Army) First Lieutenant (Brevet)
Unit	2nd New Hampshire Infantry 14th New Hampshire Infantry 6th Regiment, Veteran Reserve Corps 6th U.S. Volunteer Infantry
Wars	American Civil War

William Henry Parker (May 5, 1847 – June 26, 1908) was an American attorney, South Dakota politician, and American Civil War veteran. Parker served as an Assistant United States Attorney for the District of Colorado and was a member of the United States House of Representatives from South Dakota.

Parker was born in Keene, New Hampshire on May 5, 1847. He was educated locally and at age 14 joined the Union Army for the American Civil War. He served as a Private in the 2nd New Hampshire Infantry, 14th New Hampshire Infantry, and 6th Regiment of the Veteran Reserve Corps. He later received a Second Lieutenant's commission in the 6th U.S. Volunteer Infantry, and he ended the war as a Brevet First Lieutenant.

After the war Parker began law school at Columbian College (now George Washington University), from which he graduated in 1868. Parker practiced law, and in 1874 he was appointed the federal collector of internal revenue for Colorado Territory. In 1876 he was appointed Assistant United States Attorney for the District of Colorado. He moved to Deadwood, Dakota Territory (now South Dakota), in July 1877, where he continued to practice law.

Parker was a delegate to the territorial constitutional convention which led to South Dakota's statehood in 1885. A Republican, he served in the South Dakota House of Representatives in 1889. From 1903 to 1907 he was prosecuting attorney of Lawrence County.

In 1906 Parker was elected to Seat B, one of South Dakota's two at-large seats in the United States House of Representatives. He served in the 60th United States Congress from March 4, 1907 until his death.

Parker died in Deadwood on June 26, 1908. He was buried at Arlington National Cemetery, Section 3, Grave 2115.

He was the grandfather of William H. Parker, who served as Chief of the Los Angeles Police Department from 1950 to 1966.

• List of United States Congress members who died in office (1900–49)
• South Dakota's at-large congressional district
• United States congressional delegations from South Dakota

• United States Congress. "William H. Parker (id: P000073)". Biographical Directory of the United States Congress.
• William H. Parker's biography from US GenWeb.
• William H. Parker's historical listing at the South Dakota Legislature website.
• William H. Parker at Arlington National Cemetery
• William H. Parker, Late a Representative from South Dakota