ABSTRACT In today's technologically advanced and environmentally challenging landscape, enhancing global scientific literacy is increasingly imperative. A solid grasp of scientific principles is vital for fostering innovation and achieving sustainable development worldwide. Utilizing data from the International Association for the Evaluation of Educational Achievement (IEA) Trends in International Mathematics and Science Study (TIMSS), this study inquiries into various factors impacting grade eight students' science literacy in the TIMSS 2019 assessment. Exploring student socioeconomic status, cultural background, attitudes towards science, school organisation, teacher experiences, and country-level variables, we aimed to identify predictive associations with science literacy. Additionally, we correlated TIMSS 2019 results with the United Nations Development Program's Human Development Index (HDI). Employing three-level Hierarchical Linear Modeling, we assessed which student, teacher, and country-level variables were linked to grade 8 science literacy. Results indicate that the students' socioeconomic resources and motivation/confidence in science positively influence science literacy. Conversely, a higher percentage of science items covered in national curricula was weakly associated with lower science literacy scores. Teachers reporting greater teaching limitations due to student needs showed negative correlations with science scores. At the country level, the HDI emerged as the strongest correlate with grade 8 science literacy. These findings underscore the multifaceted nature of science literacy and its interplay with various socio-cultural and educational factors on a global scale.