William Loughridge (July 11, 1827 – September 26, 1889) was a pioneer attorney, judge, and three-term United States Congressman from Iowa. He was born in Youngstown, Ohio, where he attended the common schools. After studying law, he was admitted to the bar in 1849 and commenced practice in Mansfield, Ohio. He moved to Iowa in 1852 and settled in Oskaloosa, in Mahaska County. He served as a member of the Iowa Senate from 1857 to 1860. In 1861 he became a judge of the sixth judicial circuit of Iowa, serving until 1867.