can refer to:
- Bisexuality, in human sexuality, describes a man or woman that is sexually or romantically attracted to persons of both sexes.
- Bisexual flower, in botany, one that possesses both male (pollen-producing) and female (seed-producing) parts; see also Plant sexuality
- Bisexual species, in biology, one that has members of two different distinct sexes (e.g. humans), opposed to unisexual (only one sex present, always females).