Here, we present the Oxford Cognitive Screen-Plus, a computerised tablet-based screen designed to briefly assess domain-general cognition and provide more fine-grained measures of memory and executive function. The OCS-Plus was designed to sensitively screen for cognitive impairments and provide a differentiation between memory and executive deficits. The OCS-Plus contains 10 subtasks and requires on average 24 min to complete. In this study, 320 neurologically healthy ageing participants (age M = 62.66, SD = 13.75) from three sites completed the OCS-Plus. The convergent validity of this assessment was established in comparison to the ACE-R, CERAD and Rey-Osterrieth. Divergent validity was established through comparison with the BDI and tests measuring divergent cognitive domains. Internal consistency of each subtask was evaluated, and test-retest reliability was determined. We established the normative impairment cut-offs for each of the subtasks. Predicted convergent and divergent validity was found, high internal consistency for most measures was also found with the exception of restricted range tasks, as well as strong test-retest reliability, which provided evidence of test stability. Further research demonstrating the use and validity of the OCS-Plus in various clinical populations is required. The OCS-Plus is presented as a standardised cognitive assessment tool, normed and validated in a sample of neurologically healthy participants. The OCS-Plus will be available as an Android App and provides an automated report of domain-general cognitive impairments in executive attention and memory.