The aim of the current study is to examine the role of personality traits in self-other agreement in happiness and life-satisfaction which are often seen as the essential components of subjective well-being (SWB). Self-reports on the SWB measure and the NEO Personality Inventory-3 were obtained from 1,251 Estonians aged between 18 and 86 years. Other-ratings on the same measures were provided by knowledgeable informants. The measure of SWB showed significant self-other agreement, r = .55 (p = .000). We found this agreement to be transmitted (i.e., mediated) through the self- and other-rated personality facet scores of N3 (Depression) and E6 (Positive Emotions), Z = 2.8001 - 11.7142. The findings suggest that when an informant evaluates someone's happiness or life-satisfaction, his / her rating is inflated by the image held about the personality of this person. Furthermore, self-reported SWB reflects, to some extent, what other people think about one's personality.