This systematic review examines the application of adsorbent materials for the removal of heavy metals in continuous flow wastewater treatment systems, emphasizing their effectiveness, regeneration potential, and scalability in real-time industrial and municipal settings. Heavy metal contamination, originating from industries such as electroplating, mining, and battery manufacturing, poses severe ecological and public health risks. Continuous flow systems offer operational advantages over batch processes, including consistent throughput, automation compatibility, and suitability for large-scale applications. However, their efficiency is highly dependent on the choice and behavior of adsorbent materials under dynamic hydraulic conditions. A total of 112 peer-reviewed studies published between 2000 and 2024 were reviewed to evaluate natural, synthetic, and hybrid adsorbents including activated carbon, biochar, zeolites, metal-organic frameworks (MOFs), nanocomposites, and functionalized biopolymers. Key parameters influencing adsorption performance such as flow rate, contact time, column bed height, particle size, pH, and competing ions were analyzed across various experimental setups. The Langmuir and Thomas models were commonly used to describe breakthrough behavior and adsorption kinetics under continuous flow conditions. The review also explores adsorbent regeneration techniques including thermal treatment, chemical desorption, and microwave-assisted processes, highlighting their economic and environmental implications. Advances in fixed-bed, packed-bed, and fluidized-bed reactor designs are discussed, along with integration opportunities into existing treatment frameworks. Additionally, recent innovations using magnetic adsorbents and 3D-printed media are evaluated for their operational flexibility and ease of separation. Despite progress, significant gaps remain in translating lab-scale results to full-scale, long-term operations, particularly regarding adsorbent durability, fouling resistance, and metal recovery. Furthermore, sustainability assessments regarding life-cycle impacts and disposal practices of spent adsorbents are limited. This review concludes by recommending multi-criteria optimization approaches and hybrid system development to enhance removal efficiency and operational resilience. The findings provide valuable insights for environmental engineers, researchers, and policymakers seeking sustainable solutions to heavy metal pollution in continuous water treatment infrastructures.