William Henry Hinrichsen (May 27, 1850 – December 18, 1907) was a U.S. Representative from Illinois. Hinrichsen was Sheriff of Morgan County from 1880 to 1882. He afterwards turned to publishing interests, owning the Illinois Courier and Quincy Herald. Hinrichsen became involved with the Democratic Party in 1888, eventually rising to the position of Secretary of State of Illinois in 1892. During his term, he was elected Chairman of the state Democratic Committee. He was then elected to the United States House of Representatives and served one term. He briefly edited the Cincinnati Enquirer and spent the rest of his life writing.
William Henry Hinrichsen was born in Franklin, Illinois on May 27, 1850, the son of Edward S. and Nancy Ann Hinrichsen. He attended public schools and the Illinois Industrial University at Champaign. Graduating in 1870, he took a job as a station agent for the Northern Cross Railroad in Alexander. He was elected Justice of the Peace of Alexander in 1871 and was reelected in 1873. He married Louise Sparks on July 13, 1873.
Hinrichsen was appointed Deputy Sheriff of Morgan County in 1874 and served three two-year terms in that position, residing at Jacksonville. He served as Sheriff from 1880 to 1882. In 1882, while serving as Sheriff, Hinrichsen became editor of the Illinois Courier, a weekly newspaper in Jacksonville. In 1883, he pushed to have it become a daily paper.