Family caregivers of patients with end‐stage renal disease (ESRD) experience significant caregiver‐related burden, yet the contribution of their functional health literacy (FHL) to caregiving burden has not been elucidated. We investigated the magnitude of FHL and caregiving burden and their association in a descriptive, correlational cross‐sectional study of family caregivers of Jordanian patients with ESRD (N = 88). The short versions of the FHL for Adults and the Zarit Burden Interview were used for assessment of caregivers. Demographic and clinical information of patients and their family caregivers were self‐reported. Of family caregivers, 41% had limited FHL and 38% experienced high caregiver burden. FHL and history of comorbidity in family caregivers predicted caregiving burden independent of demographic and clinical factors. Consideration of FHL in support interventions for family caregivers may minimize some of the high perceived caregiving burden, but clinical trials of such interventions are needed to confirm this conclusion.