This thesis provides a comprehensive review of an emerging criminal phenomenon: online sexual extortion. The conduct is part of a growing category of criminal acts characterised by the use of technology to commit sexual offences. This research follows on from recent academic, media and political discussion on related issues such as the non-consensual distribution of intimate images and ‘up-skirting’. However, unlike these wrongs, online sexual extortion has received little treatment, particularly from a Scottish perspective. In examining this issue, the thesis begins by drawing on existing literature in formulating a definition of online sexual extortion, with a broad definition being advocated. In recognising that the conduct is highly differentiated, a typology of the conduct is presented by reference to cases reported in the media and discussed in the literature. The focus then turns to coverage of the problem in Scotland. This is done by providing a review of leading literature on both the law and wider issues in this area. Statistical data is then analysed in order to chart the scale of the problem in Scotland, with it being concluded that online sexual extortion represents a growing threat that requires intervention. The thesis proceeds by examining the nature of the harms. It is argued that a distinct range of harms are experienced by victims and that these harms are exacerbated by the use of technology. Building on this, the multiple ways in which the conduct may infringe a victim’s sexual autonomy are discussed. It is proposed that the wrong must be characterised as a sexual offence and that there are important conceptual and practical consequences of doing this. Additional violations in terms of damage to privacy and reputation along with financial harm are also examined. It is concluded that these factors collectively contribute to online sexual extortion being treated as a distinct criminal wrong. In assessing how well existing laws capture these harms and the wrongs of online sexual extortion, an evaluation of the criminal law framework in Scotland is then undertaken. Although acknowledged that there exist a number of offences that a perpetrator may be prosecuted under, it is argued that the response is far from satisfactory. This thesis concludes that legislative intervention would fill a gap in the current criminal law response. This could be achieved by introducing a discrete offence aimed at capturing more serious instances of sexual extortion. This would have important benefits in terms of reflecting the severity of the wrongdoing, the broader pattern of control, and range of harms experienced. It would additionally help raise awareness and be more effective in respect of fair labelling. A suggestion as to what the key elements of such an offence should be is offered in the final section of the thesis.