Purpose: To date, research studies in most disciplines have not made sex-based analysis a priority despite increasing evidence of its importance. We now understand that both sex and gender impact medication prescribing, use, and effect. This is particularly true for older adults with dementia who have alterations in drug metabolism, drug response, and the permeability of the blood–brain barrier. To better understand the influence of sex and gender on drug use in older adults with dementia, we conducted a scoping review. Methods: This scoping review systematically searched the Medline, Embase, Web of Science, CINAHL, and ProQuest databases to find published reports on polypharmacy in populations of older adults with dementia that included a sex- or gender-based analysis. Results: A total of 12 published reports were identified. Findings were cohort studies and case-control trials that commented on sex-related differences in medication use as a secondary analysis to the studies’ primary objective. These studies showed that community-dwelling women received more potentially inappropriate medications and more psychotropic medications, while nursing home dwelling men received more potentially inappropriate medications, cholinesterase inhibitors, and antipsychotics. None of the identified studies explicitly examined gender-related differences in medication use. Conclusion: This scoping review supports that there is inadequate understanding of both sex and gender differences in drug use in older men and women with dementia. To tailor medication-specific interventions to improve drug therapy for older adults with dementia, it is important that future work includes sex- or gender-based analysis of drug use.