Sleep is vital for health and recovery, but following a brain injury, up to 70% of people experience difficulties sleeping. Poor sleep substantially effects levels of fatigue, depression, ability to function at work, and impairs recovery following injury. This feasibility study aims to explore if an interactive, online treatment programme that has been found to improve sleep for people with insomnia, is feasible to use for people who have sleep difficulties following a brain injury. We will test the use of online assessments, acceptability of the programme, and recruitment timeframe, and see if there are any trends in improvement. Addressing these issues will allow us to conduct a clinical trial to determine if this potentially low-cost intervention can effectively improve sleep, and thereby improve outcomes after a brain injury, including people’s cognitive ability; depression; fatigue; and ability to return to, and perform well, at work.