BackgroundThe older adults of refugee camps might be vulnerable to exhibiting limited functional abilities because of the limited resources available to create a supportive environment for older population in the camps. This study aims to explore the prevalence and determinants of self-reported functional status among the older adults residing in the Rohingya refugee camp in Bangladesh.MethodsThis cross-sectional study was conducted on 864 older adults aged 60 years and above living in five selected sub-camps of Rohingya refugee camp in Cox’s Bazar, Bangladesh. Data were collected through face-to-face interviews of the participants between November-December 2021. Functional status was measured using the Barthel Index. Information on participants’ sociodemographic characteristics, self-reported chronic diseases and lifestyle characteristics were also collected. A multiple logistic regression model was used to assess the factors associated with self-reported functional abilities among the participants.ResultsThe overall percentage of people having limited self-reported functional ability was 26.5% (male: 22.6% and female: 31.5%) with inability most found in grooming (33.2%), bathing (31.8%), stair using (13.2%) and mobility (10.7%). In the final adjusted model, having age of 80 years or more (aOR = 2.01,95% CI: 1.08,3.75), being female (aOR = 1.44, 95% CI: 1.04,2.0), having low memory or concentration (aOR = 1.83, 95% CI: 1.30,2.56), loneliness (aOR = 2.89, 95% CI:1.74,4.80) and living with aid alone (aOR = 2.89, 95% CI: 1.74,4.80) were found to be associated with self-reported limited functional ability.ConclusionThe findings of this study highlight the need for attention from policymakers and public health practitioners on addressing functional limitations among older adults residing in the Rohingya refugee camp. Our findings emphasize the need for the development of comprehensive interventions that can address the wider unmet needs (e.g., ensuring family/caregiver support, engaging in social and physical activities, providing nutritional support packages, etc.) to improve the health and well-being of older Rohingya adults.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12877-023-04067-x.