{Character strengths are positively valued personality traits that are assumed to be stable across time and situations, but also malleable due to cultivation or deliberate intervention. Also, studies showed that character strengths are robustly related to well-being. Consequently, character strengths have often been used in interventions aimed at increasing well-being. However, the stability of character strengths and the longitudinal relationships with well-being are widely unexplored: First, previous reports on the stability of character strengths have mainly focused on one assessment instrument only and second, they did not consider other indicators of stability (and malleability) besides rank-order stability, (i.e., mean-level stability). In this longitudinal study, we assessed character strengths and well-being at two time points and examined the stability and malleability of character strengths and the convergence of changes in character strengths and well-being by means of correlation analyses. Two samples (n1 = 601