Background: Low back pain (LBP) is a leading global cause of disability with major personal and socioeconomic impact. Limitations of purely biomedical treatment have encouraged a shift toward holistic, biopsychosocial, and evidence-based management. This systematic review examined the effects of holistic, non-surgical interventions on pain, disability, muscle strength, walking balance, and quality of life in adults with LBP. Methods: A comprehensive search of PubMed, MEDLINE, CINAHL, EMBASE, Cochrane Library, Google Scholar, and HMIC was conducted. Randomized controlled trials (RCTs) involving adults (≥18 years) receiving holistic interventions including structured exercise, patient education, psychologically informed therapy, manual therapy adjuncts, or multidisciplinary rehabilitation were included. Two reviewers independently screened studies, extracted data, and assessed quality using the PEDro scale. Of 5,326 identified records, 43 RCTs met eligibility criteria. Data were synthesized narratively and through meta-analysis following PRISMA guidelines. Results: Forty-three moderate- and high-quality RCTs involving 4,144 participants were included. Holistic interventions consistently reduced pain intensity and functional disability, with meaningful improvements across intervention types. Exercise-based therapies enhanced muscle strength, endurance, and movement function, while balance outcomes improved but varied across studies. Mind–body and psychologically informed interventions (e.g., CBT, mindfulness, yoga) showed strong positive effects on psychosocial outcomes and quality of life. Multimodal programs combining exercise, education, and psychological components produced the most comprehensive and sustained improvements, outperforming single-modality interventions. Thirty-eight RCTs (n = 1,701) contributed to the meta-analysis. Exercise-based interventions significantly reduced pain (MD = –2.45; 95% CI: –3.28 to –1.62). Technology-assisted interventions were also effective (MD = –2.24; 95% CI: –2.52 to –1.97). Manual and complementary therapies produced the largest effect (MD = –2.53; 95% CI: –4.23 to –0.82). Mind–body and psychological interventions showed no statistically significant pooled effect (MD = –0.44; 95% CI: –1.56 to 0.69). Conclusion: Holistic, evidence-based, non-surgical interventions are safe and effective for improving pain, function, and quality of life in adults with LBP. Findings reinforce current international guidelines advocating biopsychosocial, patient-centred care. Clinical practice should emphasize individualized, supervised exercise integrated with psychological strategies and education. Protocol Registration: The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD420251166635.