Objective: To identify barriers and facilitators to help seeking for a dementia diagnosis from the perspective of carers and people with dementia.Design: A systematic review of the literature was conducted according to the PRISMA guidelines (PROSPERO protocol registration CRD42018092524). Nine electronic databases were searched for qualitative, quantitative, and mixed methods primary research studies. Two independent reviewers screened titles and abstracts, full texts of eligible studies, and conducted quality appraisal of included articles. A convergent qualitative synthesis approach was used. Results: From 7496 articles, 35 papers representing 32 studies from 1986 to 2017 were included. Studies originated from 13 countries across 4 continents. Barriers and facilitators were reported predominantly by carers. A small number of studies included people with dementia. Barriers included denial, stigma and fear, lack of knowledge, normalization of symptoms, preserving autonomy, lack of perceived need, unaware of changes, lack of informal network support, carer difficulties, and problems accessing help. Facilitators included recognition of symptoms as a problem, prior knowledge and contacts, and support from informal network. Conclusions: Studies from a 30-year period demonstrated that barriers to help seeking persist globally, despite increasing numbers of national dementia policies. Barriers and facilitators rarely existed independently demonstrating the complexity of help seeking for a diagnosis of dementia. Multiple barriers compounded the decision-making process and more than one facilitator was often required to overcome them. Multi-faceted interventions to reduce barriers are needed, one approach would be a focus on the development of dementia friendly communities to reduce stigma and empower people with dementia and carers.