Abstract: In recent years, China’s livestock industry has flourished, becoming a crucial component of the nation’s food supply chain by consistently producing abundant meat, eggs, and dairy products. However, this rapid industrial growth has inadvertently led to the generation of significant volumes of livestock wastewater, posing a considerable environmental threat. This wastewater, laden with organic matter, nitrogen, and phosphorus pollutants, necessitates efficient treatment to mitigate its adverse effects on aquatic ecosystems. Among the various treatment technologies, flocculation has emerged as a preferred method due to its effectiveness in solid-liquid separation within livestock operations. Despite its widespread adoption, there remains considerable uncertainty regarding the effectiveness of different flocculants in removing specific pollutants from livestock wastewater, necessitating further research. To address this, a comprehensive meta-analysis was conducted in this study, analyzing 1,194 observations sourced from 55 articles. The findings provide valuable insights into the efficacy of flocculation treatment. The results indicate that the use of flocculants can significantly enhance the removal of suspended solids in livestock wastewater. Specifically, total solids and volatile solids removal rates increased by 62.95% and 70.55%, respectively, facilitating the effective separation of nutrient elements. Notably, the removal rates of total nitrogen, total ammonia nitrogen, total phosphorus, and total potassium were also significantly improved, with increases of 37.53%, 48.04%, 69.95%, and 23.28%, respectively. These findings underscore the critical role of flocculation in managing livestock wastewater pollutants. The study further revealed that the flocculation effect is influenced by both the types of flocculants and the specific characteristics of the livestock wastewater. Inorganic flocculants exhibited superior removal effects on total solids, total phosphorus, and total potassium, while organic flocculants demonstrated the highest removal rate for total nitrogen. Composite flocculants, combining the advantages of both inorganic and organic flocculants, showed the best removal rates for volatile solids, total ammonia nitrogen, and, notably, total phosphorus, showcasing their versatility and effectiveness in treating a broader range of pollutants. The content of organic matter and nutrients in livestock wastewater emerged as a pivotal factor affecting flocculation effectiveness. Specifically, when the chemical oxygen demand is less than or equal to 10 g·L⁻¹, inorganic flocculants achieved the highest removal rates for TS, chemical oxygen demand, and total phosphorus. Conversely, when chemical oxygen demand exceeds 10 g·L⁻¹, composite flocculants demonstrated the best removal rates for chemical oxygen demand, total ammonia nitrogen, and total phosphorus. This highlights the importance of selecting the appropriate flocculant based on the specific characteristics of the livestock wastewater. In conclusion, optimizing the combination of flocculants based on the specific characteristics of livestock wastewater is an effective strategy to enhance pollutant removal rates. This approach not only improves wastewater treatment efficiency but also aligns with green and sustainable development principles. Future research should continue to explore optimal flocculant combinations and wastewater characteristics to further refine and enhance this method, ultimately contributing to the protection of aquatic environments and promoting sustainable livestock production.