Lothar Popp (7 February 1887 – 27 April 1980) was a German revolutionary and a leader of the sailors' revolt in Kiel in 1918.

Lothar Popp was born 7 February 1887 in the small German town Furth im Wald as son of a lower public servant (royal Bavarian station master); he was Catholic by denomination but left church later.

In 1915 he became a private for twenty months; in early 1917 he was dismissed as unfit for service to Kiel, to become a mobilised fitter working at the Germania ship yard.

Chairman of the USPD region Wasserkante (water edge) was a member of the Reichstag from Bremen Alfred Henke.

The USPD shop stewarts tried several days until they managed to find work for him at Gebrueder Genimb-Motorenwerke.

[2][4] In November 1918 he and Karl Artelt led the marines' mutiny in Kiel, which triggered the German Revolution of 1918–1919.

Popp took part in negotiations between sailors, SPD and USPD party delegates and navy admirals especially Wilhelm Souchon.

After Karl Artelt had spoken as a representative of the soldiers' councils, Popp presented comprehensive minimum demands to the military and political leadership: abolishment of the crown, abolition of all German monarchies, a free people's republic, a just election legislation, freedom of the press and complete release of all political prisoners.

[8] This, however, probably only pro forma, because he emphasized in later interviews that he had not cared about the Soldiers' Council since the decision for the National Assembly had been made.

[4] The effects of his then work he evaluated 1978 in retrospect as follows: "We were not revolutionaries, because we did not fight for a cause but we wanted to terminate a crazy thing.

In the New York passenger lists, 1820–1957 the following entry was made: Lothar Popp, 54 years, single, merchant, born in Furth, Germany, visa issued in Marseille, France, last permanent residence: France, Marseille arrives at 6 June 1941 on board the S.S. Evangeline from Trinidad.BWI.

He was received by Max Brauer, Herbert Weichmann and Rudolf Katz and could stay temporarily in a house rented by SPD emigrants.

Additionally, he established together with Richard Kramer the small shop "ELK Company" at 240 East 86th Street in New York, where they manufactured and sold sweets, especially marzipan.

Thereafter he came back often to stay for some months, the family also visited him in the States until he finally settled in Hamburg again.

Ernst Harberger, Lothar Popp's half brother became after second world war chairman of the professional work group for the ambulant tradespersons until he died.

Lothar Popp was interviewed for German television documentaries regarding his role during the sailors' mutiny in Kiel.