Izrael Kalman Poznanski (1833 in Aleksandrów – 1900 in Lódz) was a Polish-Jewish businessman, textile magnate and philanthropist in Lódz, and the husband of Elenora Hertz Poznanski.
The mausoleum of Izrael and Eleonora Hertz Poznanski 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.
His complex of mills in Lódz, Poland, have been turned into the 69-hectare (170-acre) Manufaktura mixed-use development, including a mall, 3 museums, multi-cinema and restaurants.