The study introduces a novel class of tough and viscoelastic hydrogels composed of polyampholytes, which are polymers with randomly dispersed cationic and anionic repeat groups. These hydrogels exhibit high toughness and viscoelasticity due to the formation of multiple ionic bonds with varying strengths. Strong bonds serve as permanent crosslinks, providing elasticity, while weak bonds break and reform reversibly, dissipating energy. This supramolecular structure allows for tuning of multiple mechanical properties, including stiffness, strength, toughness, damping, fatigue resistance, and self-healing, over wide ranges by using different ionic combinations. The hydrogels are non-toxic, anti-fouling, and have excellent biocompatibility, making them promising candidates for structural biomaterials. The synthesis method is simple and scalable, offering a wide range of mechanical properties for various applications.The study introduces a novel class of tough and viscoelastic hydrogels composed of polyampholytes, which are polymers with randomly dispersed cationic and anionic repeat groups. These hydrogels exhibit high toughness and viscoelasticity due to the formation of multiple ionic bonds with varying strengths. Strong bonds serve as permanent crosslinks, providing elasticity, while weak bonds break and reform reversibly, dissipating energy. This supramolecular structure allows for tuning of multiple mechanical properties, including stiffness, strength, toughness, damping, fatigue resistance, and self-healing, over wide ranges by using different ionic combinations. The hydrogels are non-toxic, anti-fouling, and have excellent biocompatibility, making them promising candidates for structural biomaterials. The synthesis method is simple and scalable, offering a wide range of mechanical properties for various applications.