Szlama Ber Winer, nom de guerre Yakov (Ya'akov) Grojanowski (23 September 1911 – c. 10 April 1942), was a Polish Jew from Izbica Kujawska, who escaped from the Chełmno extermination camp during the Holocaust in Poland. Szlamek (the diminutive form of Szlama) is sometimes incorrectly referred to as Szlamek Bajler in literature by the surname of his nephew, Abram Bajler, from Zamość (see postcard).