Learning motivation among elementary school students has become an increasingly pressing concern as traditional instructional methods struggle to sustain engagement in the digital era. Gamification, defined as the integration of game design elements such as points, badges, leaderboards, and narrative structures into non-game educational contexts, has emerged as a promising pedagogical strategy to address this challenge. This article presents a systematic literature review examining the relationship between gamification and learning motivation in elementary education, synthesizing findings from twenty-five peer-reviewed studies published primarily between 2021 and 2026. Using a structured narrative synthesis approach guided by PRISMA principles, the review analyzes how specific game elements, implementation contexts, and learner characteristics moderate motivational outcomes across subjects including science, mathematics, language, computer science, and physical education. The findings indicate that gamification produces a consistent, small-to-moderate positive effect on intrinsic and extrinsic motivation, with elementary learners showing comparatively larger effect sizes than secondary or higher education students. However, effectiveness depends heavily on adaptive design, balanced competition, and alignment with self-determination theory principles of autonomy, competence, and relatedness. The novelty of this review lies in its exclusive focus on elementary-level evidence and its identification of an implementation-fidelity gap that existing meta-analyses overlook. Implications for teacher training, curriculum design, and future research directions are discussed.