The introduction of Industrial Revolution (IR) 4.0 has signalled a transformation of traditional manufacturing landscape to intelligent production systems and advanced technologies. Additive manufacturing (AM) is a vital element in this latest revolution due to its remarkable potential in providing a green fabrication alternative with advanced design flexibility that surpasses the traditional manufacturing methods. At present, polymer-based additive manufacturing has drawn considerable interest in wastewater research due to its notable design freedom in manufacturing of novel, geometrically complex, and porous structures used in membrane modules and spacers, adsorption, advanced oxidation process, bioreactor, and microfluidic technology. In this work, recent advances of additively manufactured polymeric materials and 3D printing techniques used for various wastewater research are reviewed. Furthermore, the challenges in the fabrication techniques are assessed, alongside with the discussion on future perspectives of polymer-based AM technologies to develop a versatile and sustainable wastewater treatment system at commercial scale.