This study investigated how college students (N = 376) at a private, selective university (a) define success in college in their own words, and how conceptions of success (b) relate to differences in motivation and other individual differences, and (c) predict well-being. A thematic analysis suggested that students' definitions of success were multifaceted, but the most common themes reflected academic and social criteria for success. Students who defined success in terms of "Experience" (e.g., trying new things) and "Future-Readiness" (e.g., preparedness to handle life after college) tended to be higher in mastery orientation and intrinsic motivation. Success definitions varied with demographic characteristics, including gender, class year, race, first-generation status, academic interests, and more, in ways that likely reflect differences in students' cultural backgrounds and interests. Finally, well-being was higher in students who defined success in terms of "Intellectual Growth" (e.g., learning, being challenged, determining academic interests). We discuss the implications of these findings for practice (e.g., for university administrators, faculty, and advisors) and for future research.