Speech-writing skill is a crucial competency that elementary school students must master. However, in reality, fifth-grade students at SD Negeri 074049 Teluk Belukar still struggle with structuring speeches, developing ideas, and using language that adheres to proper conventions. Furthermore, the instructional process remains focused on final outcomes, and the implementation of assessments that evaluate the students' learning process is not yet optimal. This study aims to improve speech-writing skills through the application of authentic assessment combined with the Think–Pair–Share (TPS) learning model. This study is a Classroom Action Research (CAR) project. It was conducted over two cycles, each comprising the stages of planning, implementation, observation, and reflection. The research subjects were 20 fifth-grade students. Data collection techniques included observation, performance assessment, portfolios, and self-assessment. The data were analyzed using both descriptive qualitative and quantitative methods. The results indicated that in Cycle I, the students' speech-writing skills were still low, characterized by difficulties in selecting a topic, structuring an outline, and developing the content of the speech. A significant improvement was observed in Cycle II, with the majority of students demonstrating the ability to write speech texts systematically, develop ideas more effectively, and use more precise language. Furthermore, student engagement and active participation in the learning process also increased. Based on these findings, it can be concluded that the implementation of authentic assessment using the Think–Pair–Share (TPS) learning model can enhance the speech-writing skills of fifth-grade students at SD Negeri 074049 Teluk Belukar.