The selection of environmentally sustainable suppliers has historically posed a significant challenge in management decision-making (DM). Organizations must adopt a comprehensive strategy by evaluating prospective suppliers based on their competencies, financial sustainability, and ecological impact. Several studies have proposed ranking methodologies for selecting environmentally sustainable suppliers, as new models with enhanced capabilities offer greater environmental benefits. However, much research has revealed deficiencies in the confidence levels of decision-makers when providing judgments, which significantly affect the final ranking outcomes. The Pythagorean linguistic number (PLN) concept has proven to be a valuable tool for addressing multi-attribute decision-making (MAGDM) by incorporating experts’ confidence levels and addressing challenges in complex real-world scenarios. Furthermore, in modern multicriteria group decision-making (MCGDM), expert opinions often influence one another, and experts frequently exhibit subjective, bounded rationality during the decision-making process. This research presents a novel approach that utilizes an extended MULTIMOORA-based Pythagorean linguistic multicriteria quantum group decision-making methodology to address these issues. A numerical example is provided to illustrate the proposed methodology, focusing on the selection of environmentally sustainable suppliers. Finally, we demonstrate the applicability and effectiveness of the method.