Abstract Objectives The concept of health literacy (HL) is globally evolving, and understanding its nature and impact is essential for disease prevention and treatment. Therefore, we aimed in this study to assess level of HL and predictors of inadequate HL in Jordanian population as an example case of a developing country. Method This cross-sectional study was conducted in a public tertiary hospital and community pharmacies in Jordan. All respondents answered a questionnaire, which included demographic data, Rapid Estimate of Adult Literacy in Medicine-Revised (REALM-R), Short Test of Functional HL in Adults (S-TOFHLA), and All Aspects of HL Scale (AAHLS). Chi-square test and logistic regression analysis were conducted to determine the relationship and significant predictors for HL. Key findings Among 310 participants, REALM-R showed that around 27.1% had limited HL. Similar findings with S-TOFHLA and AAHLS were shown with a mean score 25.6 out of 35 (SD = 3.54, Range = 16–33) for AAHLS. Functional and critical HL were comparably low. Education level, age, living area and chronic conditions were significant predictors of HL (P < 0.05). Conclusions Health literacy was inadequate among Jordanians. Further research is required to assess the effect of inadequate HL on healthcare access and health outcomes. Health education programmes are required to improve HL particularly for patients with chronic diseases.