Jakub Lejkin (born 1906, died October 29, 1942 in Warsaw) was a Polish lawyer, deputy commander subordinate to the Germans at the Warsaw Ghetto. He was the administrator from May to July 1942 (after the temporary arrest by the Gestapo of Józef Szeryński). Lejkin played a leading role in the deportation of local Jews to extermination camps. The Germans nicknamed him “little Napoleon” and adored his brutality. His father was a wealthy tradesman. Lejkin graduated from the Polish military school in Jarocin. Before the war, he worked as a lawyer in Warsaw.