IntroductionDementia is a public health issue and a major risk factor for poor quality of life among older adults. In the absence of a cure, enhancing health-related quality of life (HRQoL) of people with dementia is the primary goal of care. Robust measurement of HRQoL is a prerequisite to effective improvement. The DEMQOL suite of instruments is considered among the best available to measure HRQoL in people with dementia; however, no review has systematically and comprehensively examined the use of the DEMQOL in research and summarised evidence to determine its feasibility, acceptability and appropriateness for use in research and practice.Methods and analysisWe will systematically search 12 electronic databases and reference lists of all included studies. We will include systematically conducted reviews, as well as, quantitative and qualitative research studies that report on the development, validation or use in research studies of any of the DEMQOL instruments. Two reviewers will independently screen all studies for eligibility, and assess the quality of each included study using one of four validated checklists appropriate for different study designs. Discrepancies at all stages of the review will be resolved by consensus. We will use descriptive statistics (frequencies, proportions, ranges), content analysis of narrative data and vote counting (for the measures of association) to summarise the data elements. Using narrative synthesis, we will summarise what is known about the development, validation, feasibility, acceptability, appropriateness and use of the DEMQOL. Our review methods will follow the reporting and conduct guidelines of the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis.Ethics and disseminationEthical approval is not required as this project does not involve primary data collection. We will disseminate our findings through peer-reviewed publications and conference presentations.PROSPERO registration numberCRD42020157851.