Sex determination may refer to:

Development of an organism's sex

• A sex-determination system, a biological system that directs the development of sexual characteristics in an organism
• Sexual differentiation in humans
• Sexual differentiation, the development of sexual characteristics in sexually reproducing organisms in general

Discernment of an organism's sex

• Prenatal sex discernment, prenatal testing for the discernment of the fetal sex in humans
• Sex assignment, the discernment of an infant's sex at birth
• Sexing, used by biologists and agricultural workers to discern the sex of livestock or other animals

See also

• Gender, including biological sex
• Sexual dimorphism, a phenotypic difference between males and females of the same species, used in sex discernment
• Sex differences in humans