Objective: Postoperative ileus (POI) is a known complication after spine surgery. This study comprehensively reviews the existing literature and evaluates the risk factors associated with POI after thoracolumbar and lumbar fusion surgeries. Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search was conducted for articles on ileus after the surgical treatment of spinal pathologies. Variables including gender, age, body mass index, comorbidities, approach, type of surgery performed, levels fused, anesthesia time, and length of stay were considered as the main outcomes of measurement. Meta-analyses were conducted using random models according to the between-study heterogeneity, estimated with I2. Sensitivity analysis was performed with heterogeneity greater than 50%. Results: Ten articles compromising a total of 297,809 patients met the inclusion criteria. POI after lumbar surgery had a statistically significant association with increased age, surgical time, anesthesia time, estimated blood loss, and length of stay. The pooled mean differences were 1.70 years (95% confidence interval [CI]: 1.52–1.87, P < 0.0001), 83.02 minutes (CI: 41.20–124.84, P = 0.0001), 64.97 minutes (CI: 31.43–98.50, P = 0.0001), 439.04 cc (CI: 250.60–627.49, P < 0.001), and 2.97 days (CI: 2.54–3.40, P < 0.001), respectively. Furthermore, individuals who underwent spinal fusion had higher odds of POI if they were male (odds ratio [OR]: 1.33; CI: 1.06–1.67; P = 0.01), if an anterior approach was performed (OR: 1.97; CI: 1.29–3.01; P = 0.002), or if >3 vertebral levels were fused (OR: 3.99; CI: 1.28–12.44; P = 0.02). Body mass index did not show any association with POI. Conclusions: Risk factors associated with POI after spinal fusion surgery include male gender, older age, longer surgical times, higher estimated blood loss, longer lengths of stay, greater numbers of levels of fusion, and anterior surgical approach.