The ovary is a ductless reproductive gland in which the female reproductive cells are produced. Females have a pair of ovaries, held by a membrane beside the uterus on each side of the lower abdomen. The ovary is needed in reproduction since it is responsible for producing the female reproductive cells, or ova.

During ovulation, a follicle (a small cavity in the ovary) expels an egg under the stimulation of gonadotropic hormones released by the pituitary gland, the luteinizing hormone and the follicle-stimulating hormone. The rest of the follicle, or the corpus luteum, secretes the sex hormones estrogen and progesterone, which regulate menstruation and control the development of the sex organs. The sex hormones and the gonadotropic hormones interact with each other to control the menstrual cycle.

When an egg matures, it is released and passes into the fallopian tube toward the uterus. If the ovum is fertilized by the male reproductive cell, or sperm, conception happens and pregnancy begins.

An ovary is normally firm and smooth and is about the size of an almond. Among the various reproductive tract cancers, ovarian cancer is the leading cause of death in women.