Soft skills are a collection of people management skills, important to many professions and job positions, including academic librarianship. Yet the concept of soft skills lacks definition, scope, instrumentation, and systematic education and training. This literature review explores the definition of "soft skills"; contrasts skills with related concepts, such as personality traits, attitudes, beliefs, and values; and compares a set of soft skill typologies. We discuss a number of conceptual issues associated with soft skills and suggest several lines of research to help clarify and strengthen librarians' understanding of and development of soft skills.