This study was motivated by the low level of environmental awareness among fifth-grade students at MI Nurul Hidayah, Jambi City, as evidenced by habits such as littering, failing to maintain cleanliness, and demonstrating a lack of responsibility for the school environment. This study aimed to describe the implementation of the Science, Technology, and Society (STS) learning model and to determine the improvement in students’ environmental awareness following its implementation. The study employed a Classroom Action Research (CAR) method conducted in two cycles, each consisting of planning, implementation, observation, and reflection. The research subjects comprised 32 fifth-grade students. Data were collected through observations, interviews, questionnaires, and documentation, and were analyzed using quantitative and qualitative descriptive methods. The results indicated that implementing the STS learning model improved students’ environmental awareness. The percentage of observational results increased from 42.86% in the pre-cycle to 68.13% in Cycle I and 87.18% in Cycle II. Questionnaire results also increased from 67.24% to 83.31%, while teacher activity increased from 65.00% to 83.33%. Therefore, the STS learning model was effective in creating active, contextual, and meaningful learning experiences that enhanced environmental awareness among fifth-grade students at MI Nurul Hidayah, Jambi City.