Izrael Kalman Poznański (25 August 1833–28 April 1900) was a Polish-Jewish businessman, textile magnate and philanthropist in Łódź, Congress Poland (part of the Russian Empire), and the husband of Eleonora Hertz Poznańska. The mausoleum of Izrael and his wife, Eleonora Hertz, on the New Jewish Cemetery has been described as "probably the largest Jewish grave monument in the world". The mausoleum and mosaic covering the inside of the dome were restored in 1993.
Together with Ludwik Geyer and Karol Scheibler, he was counted among the three "Kings of Cotton" in Łódź. His complex of mills in Łódź, Poland, have been turned into the 69-hectare (170-acre) Manufaktura mixed-use development, including a mall, 3 museums, a multiplex cinema, a hotel, and restaurants.