This manuscript examined mediators and moderators that may explain the link between strengths use and life satisfaction with a sample of 224 undergraduate students. A mediation model was tested hypothesizing that self-esteem would partially mediate the strengths use-life satisfaction link. Additionally, a moderated mediation model was tested examining positive affect as a moderator within the hypothesized model. Results suggest that a partial reason strengths use related to life satisfaction was due to an increased level of self-esteem. However, this finding must be taken in light of our mediation analysis being conducted with cross-sectional data, a limitation discussed in further detail. Furthermore, positive affect moderated the self-esteem-life satisfaction link, such that the link was stronger for individuals with low and moderate levels of positive affect. This manuscript addresses a major gap in the positive psychology literature by attempting to examine why strengths use relates to increased life satisfaction. Implications for research are discussed.