Irma Ida Ilse Grese (7 October 1923 – 13 December 1945) was a member of the Schutzstaffel (SS), a powerful Nazi military organization, during World War II. She was a guard at the Nazi concentration camps at Ravensbrück and Auschwitz. She was also the warden of the women's part of Bergen-Belsen concentration camp.

Grese was nicknamed "the Hyena of Auschwitz" (German: die Hyäne von Auschwitz) by prisoners there because of the cruel ways she treated them. After World War II ended, Grese was put on trial for war crimes at the Nuremberg Trials. She was convicted of crimes against humanity for the things she did at Auschwitz and Bergen-Belsen. She was executed in 1945 at age 22.