John Peter Altgeld (1847 - 1902) was the governor of Illinois from 1893 until 1897. He was the first U.S. Democratic Party governor of that state since since the 1850s.

Altgeld, a German immigrant to the United States, became a lawyer in Missouri and later moved to Illinois. Before his election as governor he was already known for sympathizing with the problems of farmers and laborers. As governor, he pardoned the surviving suspects of a bombing who were convicted after the Haymarket Riot. He also refused to call in the state militia during the Pullman Strike, a highly unusual decision for a state governor at that time. These acts made him unpopular with industrialists and conservatives, and he was defeated for reelection in 1896. Altgeld was admired by other leaders of the Progressive Era movement as one of the few incorruptable politicians who would stand up for the rights of workers.