Good sleep is critical for wellbeing – including dementia prevention and good mental health. But the COVID-19 pandemic and lockdown is placing people under huge stress, which may disturb sleep. Disturbed sleep now may have an impact on current and future health for all, in particular those at risk of dementia. The SleepQuest study needs to hear about your experiences to understand the effect that the outbreak is having and create advice on how to manage sleep throughout this crisis and beyond.