Background: Small-Sided Games (SSGs) are game-based training activities that manipulate player numbers, playing area, and task constraints to reproduce important features of match play. Although SSGs are widely used in futsal, evidence specifically addressing tactical outcomes and tactically related technical skills in high school players remains limited. Objective: This scoping review mapped empirical evidence on SSG interventions and their effects on direct tactical outcomes and tactically related technical skills among high school futsal players. Methods: The review followed Joanna Briggs Institute methodology and the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Searches were conducted in Scopus, Directory of Open Access Journals (DOAJ), and Google Scholar for studies published from 2019 to 2026. Eligible studies involved high school futsal players aged 15–18 years, used an SSG intervention, and reported a direct tactical outcome or a tactically related technical skill. Results: Of 260 records identified, 225 unique records were screened, 12 full texts were assessed, and three quasi-experimental studies met the eligibility criteria. All three studies assessed technical outcomes, particularly passing accuracy, passing skill, and dribbling; none used a validated instrument to directly assess tactical awareness, positioning, off-the-ball tactical behaviour, game intelligence, or decision-making as a primary outcome. Fitrian et al. (2023) reported improved passing accuracy after 15 SSG sessions. Purwanto et al. (2026) reported significant improvement in passing and dribbling after an eight-week SSG programme. Putra et al. (2026) reported greater improvement in passing skills in an SSG group than in a comparison group, although the source study contains inconsistencies in its description of the intervention. Conclusion: Current evidence supports the potential of SSGs to improve technical execution in school-level futsal, particularly passing-related skills. Evidence for direct tactical outcomes in high school futsal remains insufficient. Future studies should use validated tactical performance instruments, transparent intervention protocols, larger samples, and more rigorous experimental designs.