Horizontal deceleration is a key demand in multidirectional sports, but interventions deliberately targeting braking capacity, braking-load tolerance, or braking-oriented cutting mechanics have not been systematically synthesized. This systematic review and exploratory meta-analysis examined horizontal decelerationoriented training (HDOT) in multidirectional-sport athletes. Following PRISMA 2020, four databases were searched to 1 May 2026, and the protocol was registered in PROSPERO (CRD420261380073). Eligible studies included multi-session interventions in multidirectional-sport athletes. Interventions were grouped by dominant brakingrelated target as direct braking-focused HDOT, involving stopping, enforced deceleration, or prescribed stoppingdistance drills; change-of-direction (COD)-linked braking-load HDOT, involving loaded, resisted, or eccentricoverload tasks linked to deceleration or COD braking outcomes; or technique-focused HDOT, involving coaching cues, feedback, or movement retraining to modify braking-oriented COD/cutting strategy. Twenty-five studies involving approximately 670 participants were included, and 17 contributed to random-effects meta-analyses. Direct braking-focused interventions showed positive pooled estimates for 505 or modified 505 COD time, with less consistent evidence for sprint and jump outcomes. COD-linked braking-load interventions showed positive estimates for sprint or agility outcomes, whereas repeated-sprint outcomes were inconsistent. Technique-focused interventions showed positive estimates for cutting-specific performance and observable cutting movement quality, although several estimates came from small two-study pools or qualitative tools. Isolated three-dimensional biomechanical markers were inconsistent. Evidence certainty varied and was limited by small study numbers, imprecision, indirectness, task heterogeneity, and intervention heterogeneity. Overall, HDOT effects appeared subtype-specific and task-specific, supporting training selection based on the intended braking-related adaptation and stimulus–outcome match rather than the mere presence of deceleration within a drill.