Jānis Lācis (Russian: Ян Я́нович Ла́цис, Yan Yanovich Latsis; February 20, 1897 – March 10, 1937) was a Latvian Riflemen, later Soviet division commander and Komkor (corps commander).

Jānis Lācis
BornFebruary 20, 1897
Jaunpiebalga Municipality, Kreis Wenden, Governorate of Livonia, Russian Empire (Now  Latvia)
DiedMarch 10, 1937 (1937-03-11) (aged 40)
Khabarovsk, Soviet Union
AllegianceRussian Empire
Soviet Union
Service/branchImperial Russian Army
Soviet Red Army
Years of service1916–1917 (Russian Empire)
1917–1937 (Soviet Union)
RankKomkor
Commands held15th Rifle Division
16th Rifle Corps
Battles/warsWorld War I
Russian Civil War

Lacis fought in the 4th Vidzeme Latvian Riflemen Regiment of the Imperial Russian Army in World War I before going over to the Bolsheviks in the subsequent civil war. He was a recipient of the Order of Lenin and the Order of the Red Banner. From 1932 to 1937, he commanded the troops guarding the railways of Siberia and the Far East. He was simultaneously a member of the Central Executive Committee of the Russian Soviet Federative Socialist Republic. He died of an illness in Khabarovsk. He is buried at Novodevichy Cemetery.

Military offices
Preceded by
Division created
Commander of the 15th Rifle Division
June 1918 – November 1919
Succeeded by
Alexander Sirotkin
Preceded by
Commander of the 16th Rifle Corps
1930-1931
Succeeded by