Image-based sexual abuse (IBSA) involves the taking or sharing (including threats to share) of intimate images of another person without their consent. Whilst the experiences of IBSA among adults has been documented, little research has examined such experiences among youth. This study aimed to address this gap by reporting on the extent and nature of IBSA and intimate image sharing, the impacts and fears of victims, the motivations of perpetrators, and the reactions of bystanders, among youth. To achieve this aim, a survey was carried out with 293 Australian respondents aged between 16 and 20 years. Results showed that 1 in 4 respondents had been victims of IBSA and 1 in 10 had been perpetrators of IBSA. The majority had targeted, or were targeted by, those with whom they had a previous close relationship. Perpetrators in most cases were motivated by the belief that it was funny and/or sexy or flirty, to get back at the person, or to impress friends. Victims experienced negative impacts on work/study performance and relationships. Half of the respondents had been bystanders of intimate image sharing and many reported feeling uncomfortable or embarrassed when shown or sent these images. Together, these findings highlight the pervasive nature of IBSA and its impacts. Implications surrounding the importance of the peer context, focusing upon consent and healthy relationships within education, and the need to challenge victim-blaming rhetoric associated with IBSA and intimate image sharing, are considered.