Teachers’ ability to design effective reading literacy materials is essential to help students comprehend texts and foster positive attitudes toward reading. However, many teachers still face challenges in developing such materials, which often results in students’ difficulties in understanding texts. This study aims to develop reading literacy materials based on the Big Questions and Bookmark Organizers strategy for fourth-grade elementary students that meet the criteria of validity, practicality, and effectiveness. The research employed the Plomp development model, consisting of self-evaluation, expert review by three specialists, and prototype testing. Initial testing was conducted through one-to-one evaluation with students at Public Elementary School 46 Kuranji, followed by small-group and field test evaluations at Public Elementary School 06 Padang Besi to examine practicality. Effectiveness testing was carried out through field test evaluation at Public Elementary School 01 Sawahan. The results indicated that the developed materials achieved a validity score of 3.82, categorized as highly valid. Practicality reached 95.25 percent, classified as highly practical, as shown by the implementation of lesson plans, as well as positive responses from teachers and students. Furthermore, the materials demonstrated effectiveness through students’ active engagement, improvement in reading skills, development of positive attitudes, and better critical thinking outcomes. In conclusion, the Big Questions and Bookmark Organizers-based reading literacy materials for fourth-grade elementary students were proven to be valid, practical, and effective, and thus hold potential for broader application in enhancing reading instruction at the elementary level.