Otoman Zar-Adusht Ha'nish (December 19, 1856 – February 29, 1936) was the founder of the religious movement known as Mazdaznan. He was born Ernst Otto Haenisch, a German immigrant from Poznań (then Posen), son of the grocer (victualer) Heinrich Ernst Haenisch and his wife Anna Dorothea nee Schmidt. He was baptized on December 28, 1856.