Ornstein is a surname of Jewish origin. Notable people with the surname include:
Anna Ornstein (1927–2025), Hungarian-American Auschwitz survivor, psychoanalyst and psychiatrist Axel Ornstein (b. 1952), Swedish chess master Donald Samuel Ornstein (born 1934), American mathematician Jonathan G. Ornstein, CEO of Mesa Air Group, Inc. Leo Ornstein (1895–2002), Russian-American composer Leonard Salomon Ornstein (1880–1941), Dutch physicist known for the Ornstein–Zernike equation and the Ornstein–Uhlenbeck process Michael Marisi Ornstein (born 1963), American actor Norman J. Ornstein (born 1948), American political scientist Paul Ornstein (1924–2017), Hungarian-American psychoanalyst and Holocaust survivor Robert Ornstein (1942–2018), American psychologist Severo Ornstein (born 1930), American computer scientist and son of Leo Ornstein Bernadine Dohrn (born 1942) née Ornstein, American activist and lawyer
In video games Dragon Slayer Ornstein, an enemy boss in the game Dark Souls.
See also Arnstein (disambiguation) Orenstein Gorenstein Hornstein (disambiguation)