Objectives: Carers of people with dementia face barriers in accessing therapy for mental health difficulties. Computerised cognitive behavioural therapy (cCBT) packages can be effective in treating a range of presentations; however, tailored packages for carers' unique needs are lacking. Our aim was to design a cCBT package for carers to address the limitations of previous online interventions, by including users and experts as consultants and collaborators throughout the project. Method: We adopted a three-phase approach to the development process. Firstly, a data-gathering phase in which current literature and best practice was reviewed, and semi-structured interviews conducted with service users, academic and clinical experts. Secondly, a co-production and refinement phase with carers testing materials and providing feedback. Thirdly, a pilot field testing phase of service users and the research team testing the package. Results: The ‘Caring For Me and You’ package adopted a transdiagnostic approach to take account of the range of difficulties that carers face. The package consisted of 20 short sessions with features built in to engage users and personalise content to meet individuals' needs. Conclusion: User involvement was central to the design of the ‘Caring For Me and You’ package which is currently being evaluated in a three-arm randomised controlled trial.