Most of us have experienced firsthand that the quality of our relationships significantly influences the quality of our lives. This intuition is well-supported by research on human flourishing. Yet at a time of growing polarization, institutional fragility, and relational strain, the role of trust, seen here as being relationally invested with something of value placed at risk in the hope of advancing connection, cooperation, or mutual benefit, remains underexamined in the well-being literature. This paper explores how trust enables individual and collective flourishing by generating forms of well-being capital and supporting the mechanisms identified in positive psychology. Effectively navigating relational uncertainty is considered crucial for seizing opportunities for intimacy and cooperation while mitigating the risks of betrayal, loss, or harm, and for forming, sustaining, and repairing fulfilling relationships. This paper proposes Trust Intelligence (TI) as a distinct adaptive capacity that governs these relational investments. Drawing on multiple disciplines, the paper proposes a functional model of TI, outlining its features and outputs, and argues for its potential to be measured, cultivated, and applied, particularly in leadership contexts. This paper also argues that, in its most advanced form, TI can be directed toward what is conceived as Trust Wisdom (TW), which is the ethically grounded and virtue-informed application of TI in service of dignity, fairness, and collective flourishing. Developing TI and guiding it toward TW presents a promising and necessary pathway to individual and societal well-being in a time of profound relational and institutional uncertainty.