A novel synthesized polyacrylic polyacrylamide phosphate (PAA@PAm@P) hydrogel was developed for the highly selective removal of the cationic dye Methylene blue (MB) from water. Dyes such as MB are among the most hazardous industrial wastes, as many are carcinogenic and toxic, and even at very low concentrations, they can have serious effects on ecological systems and pose significant risks to human health. MB-dye, widely used in daily life, can cause adverse health risks to humans including vomiting, respiratory difficulties, diarrhea, and nausea. The limitation of MB-molecules by cost-effective adsorbents has been recognized internationally as an effective and environmentally sustainable method. Hydrogel-based systems have emerged as a promising approach to remove these species from aquatic media owing to their mechanical properties, stimulus–response, high removal efficiency, reusability, operational simplicity, eco-friendly characteristics, and cost-effective performance.