Supplier selection plays a pivotal role in ensuring supply chain sustainability, particularly for Smart Product-Service Systems (Smart PSS) manufacturers. Smart PSS inherently integrates tangible products and intangible services, so the complexity of evaluating and selecting sustainable suppliers is significantly amplified. Traditional approaches often treat product design and supplier selection as separate decisions, which may result in suboptimal outcomes and hinder long-term sustainability goals. To address this gap, this chapter proposes a novel integrated method that simultaneously considers Smart PSS design and sustainable supplier selection within a unified decision-making model. The proposed framework incorporates multiple sustainability dimensions—including environmental, social, and economic criteria—into the evaluation process, thereby aligning supplier selection with the broader objectives of sustainable supply chain management. Furthermore, a tailored solution algorithm is developed to effectively solve the model, accommodating the multi-dimensional trade-offs inherent in Smart PSS design and supplier selection. By combining system-level design considerations with supplier performance assessment, the chapter provides both theoretical advancements and practical guidelines for manufacturers striving to build resilient and sustainable Smart PSS supply chains.