This Element examines technology-assisted grooming of children for sex - henceforth, online grooming - as an illegal practice of communicative manipulation and, as such, something that research within the academic field of forensic linguistics is ideally placed to help counter. The analysis draws upon online grooming datasets of different sizes and provenance, including from law enforcement, and deploys different analytic techniques from primarily discourse analysis. Three features of online grooming discourse are focussed on: groomers' use of manipulation tactics; groomers' abuse of power asymmetries; and children's communication during online grooming. The Element also discusses ways in which findings derived from richly contextualised analysis of online grooming discourse can - when combined with co-creation projects involving child-safeguarding groups, children and lived-experience experts - add considerable value to societal efforts to counter online grooming and other forms of online child sexual exploitation and abuse.