Dementia is an increasing challenge across the globe. The 2015 World Alzheimer Report by Alzheimer’s Disease International describes the global impact of dementia, which is summarized below (Prince et al., 2015). The prevalence of dementia is increasing worldwide with 47 million people with dementia in 2015, estimated to rise to 131 million by 2050. Dementia is the leading contributor to disability and need for care in older people, with a population-attributable fraction of 25% for disability. In people aged over 60 years globally, dementia is the ninth leading cause of Disability Adjusted Life Years (DALYs) lost and the eighth leading case of Years Lived with Disability. The global cost of dementia in 2015 was estimated to be US$818 billion. The rate of population ageing is relatively greater in low- to middle-income countries and this is compounded by a relative lack of resources. As a result, low- to middle-income countries will be impacted more dramatically by dementia compared to high-income countries. A recent review and accompanying editorial has concluded with ‘a call to action’ for greater research attention to the impact of sex in Alzheimer’s disease to help improve outcomes with an acknowledgment that insufficient attention has hitherto been paid to sex-specific issues in dementia more broadly (Mielke et al., 2018 and Nebel et al., 2018). This chapter provides an overview of dementia, with a focus on males.