Objective: Islamic population constitute more than 20% of the world population and is growing rapidly. Nevertheless, data concerning informal caregiving to older Muslim patients diagnosed with cancer are scarce. Improving the well-being of caregivers is a vital step to optimal care for the patients themselves throughout the Muslim community and the world. This study focuses on a sample of Palestinian caregivers of older Muslim patients diagnosed with cancer living in East Jerusalem, the West Bank, and Gaza. The study aims to describe the socio-demographic characteristics of the caregivers and to understand their social support, and identify predictors of caregivers’ depression. Methods: A cross-sectional study of a convenience sample of 99 dyads of Palestinian patients (age ≥65) and their informal caregivers. Depression and social support were measured using the five items of the Geriatric Depression Scale and the Cancer Perceived Agents of Social Support questionnaire. Results: Caregivers were most frequently adult children (52%) or spouses (32%), with male patients cared for by spouses (47.5%) or sons (32%), and female patients by daughters (50%). Clinical levels of depression were reported by 76% of the caregivers and 85% of patients. The significant predictors of caregiver depression were female gender, lower education, lower perceived social support from spouse and family, and higher perceived support from faith. Significance of results: Healthcare providers serving the study population should determine the position and role of the caregiver within the social and family structure surrounding the patients’ families. This understanding may facilitate overcoming barriers to effective and meaningful social support.