Contractor selection is a key aspect of construction project management, traditionally based on factors like cost, experience, quality, and past performance. With growing emphasis on environmental and social responsibility, the process now incorporates sustainability considerations. Sustainability in this context reflects a balanced integration of economic, social, environmental, and technical factors aimed at maximizing value and minimizing negative impacts. Despite growing interest, there is still a lack of comprehensive multi-criteria models that fully integrate these dimensions in contractor selection. Additionally, while the Integrated Project Delivery (IPD) method is acknowledged for its potential to enhance sustainability, its role in contractor selection remains underexplored. This research seeks to fill these gaps by developing a robust Multi-Criteria Decision-Making (MCDM) framework for evaluating sustainable contractors, incorporating insights from both academic experts and industry professionals. The study aims to expand sustainability theory by recognizing technical sustainability as a core component, alongside environmental, economic, and social aspects. It also demonstrates the effectiveness of MCDM tools such as Fuzzy AHP and Fuzzy VIKOR in facilitating sustainable contractor selection. Moreover, the research evaluates IPD as a delivery method that supports improved project outcomes through enhanced stakeholder collaboration. The research centers on the selection of sustainable contractors for a proposed multi-purpose banquet facility, using expert input and best practices from the industry. The case study illustrates the practical application of the proposed Decision Support System (DSS), showcasing its effectiveness in supporting sustainability-oriented contractor assessments within the IPD framework. Sustainability sub-criteria are refined through an extensive review of existing literature and feedback from both academia and industry. Applying MCDM techniques, particularly Fuzzy AHP and Fuzzy VIKOR, the study focuses on developing selection criteria and a decision-making framework, without delving into actual project execution or management. By addressing the current gap in sustainability-focused contractor selection and integrating IPD principles, this research introduces a comprehensive and practical framework that serves both industry professionals and academic researchers. From an academic standpoint, the study contributes an innovative, integrated MCDM model set in a fuzzy environment to combine quantitative data with qualitative expert opinions, enhancing the methodological depth of sustainability-related decision-making. It illustrates how expert-assigned weights to sub-criteria influence contractor rankings, offering insights into stakeholder-driven evaluation dynamics. From an industry perspective, the DSS presents a versatile and practical tool that brings greater consistency, transparency, and objectivity to contractor selection within IPD contexts. Its use in the banquet center case study validates its real-world applicability and showcases its potential to promote more sustainable construction practices.