Louis Lingg (September 9, 1864 – November 10, 1887) was a German-born American anarchist who was convicted as a member of the criminal conspiracy behind the 1886 Haymarket Square bombing.

He then took a job in Strasbourg, in Alsace, then moved on to Freiburg, Germany, where he joined the Working Men's Educational Society, a socialist organization.

[2] To avoid military service, Lingg moved to Switzerland, but in the spring of 1885, the police in Zürich ordered him to leave the country.

[2] In July 1885, Lingg arrived in New York City then departed for Chicago, Illinois, where he joined the International Carpenters and Joiners' Union.

Witnesses interviewed by police placed Lingg in the basement of Greif's Hall the night before the bombing, along with other accused members of the conspiracy including Rudolph Schnaubelt, the lead suspect as the bomb thrower who would have stood trial with the other accused had he not fled Chicago.

[6] Defense attorney Moses Salomon said in his opening statement to the jury: "It may seem strange why he (Lingg) was manufacturing bombs.

Salomon argued that the accused plans did not target "the life of any single individual at any time or place," and did not conspire to murder Officer Mathias Degan or any number of policemen, "except in self-defense.

Lehman was stationed outside Greif's Hall as a lookout and recalled walking home with Lingg, William Seliger and two other men.

He said Lingg anticipated a "disturbance" on the West Side and that he had spotted the word "Ruhe" (quietude) in the anarchist newspaper Arbeiter-Zeitung, the signal for armed groups to assemble.

There, a man who came from the Haymarket yelled at Lingg, "You are the fault of all of it," an incident corroborated by the testimony of Moritz Neff, the anarchist bartender.

He also stated that his wife had also been paid by the police but that he did not know how many times or how much money she received, but on further questioning said "I think twenty or twenty-five dollars.

[16] Speaking before the court at his sentencing, Lingg denounced Seliger as a "bought squealer," adding the prosecution had failed to prove that the bombs he made were taken to the Haymarket.

On June 26, 1893, Illinois governor John Altgeld pardoned three of Lingg's co-defendants - Oscar Neebe, Michael Schwab, and Samuel Fielden - and stated that they were innocent of the crime.