Core exercises (CE) are often included in rehabilitation programs following anterior cruciate ligament reconstruction (ACLR) to enhance recovery and functional outcomes. This systematic review aimed to evaluate the impact of CE on performance outcomes, pain management, and lower-limb biomechanics in individuals after an ACLR. A comprehensive search was conducted in PubMed, Web of Science, Scopus, and Embase from inception to May 3, 2025. Two independent reviewers screened studies reporting the effects of CE on pain and function in individuals with ACLR. The primary outcomes were: pain intensity, measured using the Visual Analogue Scale (VAS), Knee injury and Osteoarthritis Outcome Score-Pain subscale (KOOS-Pain), and Hospital for Special Surgery (HSS) score. functional outcomes, including self-reported function (International Knee Documentation Committee [IKDC] score, Lysholm score, Tegner activity scale), performance-based tests (single-leg hop tests), and range of motion (ROM). Lower-limb biomechanics, assessed via gait analysis, KT-1000 arthrometer, and joint reaction force analysis. The methodological quality of included studies was assessed using the Physiotherapy Evidence Database (s) scale. Meta-analysis was conducted using a random-effects model, and mean differences with 95% confidence intervals (CIs) were calculated in RevMan 5.4. Ten studies with a total of 463 participants were included. The meta-analysis suggested strong evidence of non-significant changes in VAS, KOOS-pain, and HSS scores between the CE and the traditional exercise groups. The meta-analysis demonstrated strong evidence of significant improvement in IKDC score and hop test score, along with moderate evidence of significant improvement in Lysholm and Tegner scores between the CE and the traditional exercise groups. The result of biomechanical outcomes revealed limited improvements in gait parameters. CE may offer significant benefits for functional performance, especially in IKDC scores, when combined with lower-limb strengthening programs, but their effects on pain relief and biomechanics are less consistent. Future research should focus on standardized protocols and follow-up periods to further explore the role of CE in ACLR rehabilitation.