Trust has not yet been explored by positive psychologists. This paper reviews the literature on trust, discusses four well-being models, summarizes the relationship between trust and well-being and considers implications. Two main conclusions are reached. First, a strong and significant relationship exists between trust and well-being for individuals, institutions and communities. There is some basis for hypothesizing that the main casual effect runs from trust to well-being. Second, trust’s powerful catalytic and transitive properties make it 1) essential for individual and group well-being and 2) a strategic lever for generating positive and scalable change. Two key implications are noted. First, a positive deviance of trust is called for and a new conceptualization of trust is proposed to achieve this deviance —appreciative trusting or ‘the deliberate and intentional pursuit of maximal trust in others—even to the limits of prudence’. In practice, ‘appreciative trusting’ involves vigilance in five areas: 1) becoming more trusting, 2) seizing opportunities to demonstrate to others that they are trusted, 3) zealously guarding other people's trust as a precious resource, 4) encouraging third parties to trust each other, and 5) continuing to trust in the face of disappointments. The second implication is that positive psychology should embrace trust as an area for research and application and trust researchers should seek out and collaborate with positive psychologists. Further research on the concept of ‘appreciative trusting’ is suggested.