Sexual abuse or sex abuse, also referred to as molestation, is abusive sexual behavior by one person upon another. It is often perpetrated using force or by taking advantage of another. Molestation often refers to an instance of sexual assault against a small child, whereas sexual abuse is a term used for a persistent pattern of sexual assaults.

The offender is referred to as a sexual abuser or (often pejoratively) molester. The term also covers behavior by an adult or older adolescent towards a child to stimulate any of the involved sexually. The use of a child, or other individuals younger than the age of consent, for sexual stimulation is referred to as child sexual abuse or statutory rape. Live streaming sexual abuse involves trafficking and coerced sexual acts and or rape in real time on webcam.