Oophorectomy or Oöphorectomy (; from Greek ᾠοφόρος, ōophóros, 'egg-bearing' and ἐκτομή, ektomḗ, 'a cutting out of'), historically also called ovariotomy, is the surgical removal of an ovary or ovaries. The surgery is also called ovariectomy, but this term is mostly used in reference to non-human animals, e.g. the surgical removal of ovaries from laboratory animals. Removal of the ovaries of females is the biological equivalent of castration of males; the term castration is only occasionally used in the medical literature to refer to oophorectomy of women. In veterinary medicine, the removal of ovaries and uterus is called ovariohysterectomy (spaying) and is a form of sterilization.
The first reported successful human oophorectomy was carried out by Sir Sydney Jones at Sydney Infirmary, Australia, in 1870.