Agile frameworks have redefined software development by shifting from hierarchical control to collaborative autonomy. However, this transformation is unsustainable without trust. This chapter examines trust as the foundational enabler of Agile success, arguing that it is not merely beneficial but structurally essential. Drawing on grounded theory and empirical insights, it explores how trust underpins team autonomy, knowledge sharing, distributed leadership, and the enactment of core Scrum values such as commitment and courage. Two distinct yet interdependent dimensions of trust: cognitive, based on competence and reliability, and affective, grounded in interpersonal care and shared purpose, are analysed as critical to team cohesion and adaptability. The chapter also considers how swift trust emerges in time-constrained teams, how trust supports shared decision-making and psychological safety, and how its absence leads to superficial or dysfunctional Agile practices. Ultimately, trust is presented as the unspoken architecture that sustains high-performing, self-organising teams. Without it, Agile becomes a façade, with it, teams can innovate, adapt, and collaborate with integrity and resilience.