We begin by setting out the rationale for targeting offenders, victims, and settings. For this purpose we draw primarily on Eck’s (2003) crime triangle, which proposes a motivated offender, a suitable target, and a conducive location, as the three basic prerequisites for any crime to occur. We then summarise research findings concerning sexual offenders, their victims, and the settings in which various kinds of sexual offences occur. Next we outline our rationale for focusing on three prevention levels, drawing on the public health model that distinguishes primary (or universal), secondary (or selected), and tertiary (or indicated) prevention. In the remainder of the chapter we work through each of the nine cells in the matrix, presenting examples of evidence informed prevention strategies for each target × level configuration.