Mathematical literacy is the basis for students to fully understand learning in the 21st-century era. The low mathematical literacy ability of students in elementary schools reduces the quality of education and participation of students in everyday life. Therefore, there is a need to develop learning modules to increase student literacy. Using an ethnomathematics-based teaching module with the RME approach is one solution. The goal of this development research is to create teaching modules that can improve the mathematical literacy of fifth-grade s elementary school students. The research subjects were students and teachers of fifth-grade elementary schools in Petanahan District. Observation, interviews, questionnaires, documentation, and tests are used as data collection methods. Both qualitative descriptive analysis and quantitative analysis were used to process the data. The results showed that the validation was rated as very good category by linguists 93.8%, material 94%, and design experts 92%. According to students responses, the practicality level falls within the 87.65% very good category. The effectiveness of the teaching module on mathematical literacy can be seen from the significance level 0.000 0.05, teaching module has a positive effect on improving mathematical literacy of fifth-grade students in elementary school. So, the ethnomathematics-based teaching module with a realistic mathematics education approach to improve mathematical literacy is valid, practical, and effective. Research and development of this ethnomathematics-based teaching module has been proven effective only in Petanahan District, it needs to be tested for effectiveness in a wider population so that it can be used more widely. Other researchers can develop similar teaching modules by taking ethnomathematics in other areas.