Female sex workers (FSW) experience a high HIV burden and are often mobile. FSW access to HIV-related healthcare is essential for equitable welfare and to reduce new HIV infections. We systematically reviewed the literature on mobility and HIV-related healthcare access and use among FSW. Outcome measures included: HIV/STI testing, STI treatment, PrEP (initiation or adherence), and ART (initiation or adherence). We summarised the results with a narrative synthesis. From 7417 non-duplicated citations, nine studies from Canada (3), Guatamala, Honduras (2), India, South Africa, and Vietnam were included. Only one of the studies was designed to address mobility and healthcare access, and only six reported adjusted effect estimates. Mobility was measured over four time-frames (from 'current' to 'ever'), as having lived or worked elsewhere or in another town/province/country. Three studies from Canada, Guatemala, and India found mobility associated with increased odds of poor initial access to healthcare (adjusted odds ratios (AOR) from 1.33, 95% CI 1.02, 1.75, to 2.27, 95% CI 1.09, 4.76), and one from Vietnam found no association (odds ratio (OR): 0.92, 95% CI 0.65, 1.28). The study from South Africa found no association with initiating ART (risk ratio: 0.86, 95% CI 0.65, 1.14). Two studies from Canada and Honduras found increased odds of ART interruption (AOR 2.74, 95% CI 0.89, 8.42; 5.19, 95% CI 1.38, 19.56), while two other studies from Canada and Honduras found no association with detectable viral load (OR 0.84, 95% CI 0.08, 8.33; AOR 0.79, 95% CI 0.41, 1.69). We found that mobility is associated with reduced initial healthcare access and interruption of ART, consistent with literature from the general population. Discordance between effects on adherence and viral load may be due to measurement of mobility. Future research should carefully construct measures of mobility and consider a range of HIV-related healthcare outcomes
