Addressing user needs and preferences is critically important in developing innovative and successful engineered products and systems. The task is inherently challenging due to the heterogeneity of user needs and the difficulty of modeling human behavior and preferences. In addition, it remains a challenge to integrate user preferences with technical and economic requirements during the engineering design process. The past decade has seen a significant growth in user-focused design research that introduces principles from different domains, such as market research, economics, cognitive science, and social science. However, there is still a lack of integration of these methods, either qualitative or quantitative, for directly supporting engineering design decisions. It is therefore imperative to develop interdisciplinary design approaches to address " interface " issues among different domains and engineering design, considering market demand, usage context, social behavior, environmental impact assessments, and other factors. With this in mind, we organized this Special Issue to gather state-of-the-art research in user needs and preferences, with the goal of identifying new research frontiers in this area. Over ninety technical papers were submitted for review to the Special Issue. All papers were subjected to a rigorous peer-review process with quality standards set by ASME. While the three of us served as associate editors for most of these manuscripts, we would like to thank Journal of Mechanical Design associate editor Dr. Christopher Mattson for his assistance coordinating the reviews of some of the papers. We are also very grateful to all reviewers who helped review these papers. This Special Issue collects fourteen papers including one technical brief. These papers are organized into four groups based on common themes: (1) User needs and preferences elicitation, (2) Incorporating user needs into engineering design, (3) Choice-based preference modeling and design, and (4) Modeling user behaviors and activities adapted to use contexts. The following summaries provide brief snapshots of these papers and the relationships between them.