This doctoral dissertation investigates sustainability and subjective well-being in relation to the theory and practice of design. This work draws on existing design research in these domains, along with related studies in fields including psychology and human-computer interaction. The research strands of design for sustainability and design for subjective well-being have grown over the last several decades, though have remained siloed, with minimal investigation across these high-level concerns. Limited work exists examining the compatibility or conflict between these perspectives, with potential for negative unintended consequences resulting from these siloed efforts. Generating further understanding in this area and developing strategies for practicing designers to integrate the concerns of sustainability and subjective well-being in their work, three connected areas of investigation were undertaken. The three studies sought to connect the end-users of design, the designers themselves, and the designed artifacts that unite these two groups.Chapter 1, titled Connecting sustainable behavior and subjective well-being: An experiential model for design, utilized an experience sampling method approach to identify daily activities that influenced subjective well-being and sustainable behavior simultaneously. Psychological and contextual factors involved in the relationship were identified, and a conceptual model was developed uniting and organizing the relevant factors. These findings provide researchers and practitioners with both a holistic overview, as well as targeted areas where new design interventions can be initiated. In Chapter 2, titled Sustainability & Subjective Wellbeing in Professional Design: Perspectives, Challenges, & Opportunities, the experiences of practicing design and development professionals were studied. Recent design research has noted that investigation into professional practice in this area is quite limited, with a lack of understanding on the relevance or integration of academic work on these topics. Qualitative semi-structured interviews identified challenges and opportunities at the public policy level, organizational level, within designers’ education and training, and concerns at the product design and manufacturing level. Dual pathways of strategies to improve conditions at both the design and organizational levels were developed and presented. Finally in Chapter 3, titled Should Sustainability Come Second? Artifact Analysis Toward More Positive Outcomes Through Design, utilized an artifact analysis approach to study existing designed products and systems that can positively influence subjective well-being and sustainability. This work identified attributes of existing artifacts that have been successful in this space, and created design guidelines to promote structured integration of these concerns in professional design practice in the future.