This entry introduces “leadership out of necessity” as a framework for understanding how individuals rise to lead in the absence of traditional authority, resources, or permission. While crisis leadership, transformational leadership, and systems-based leadership all offer valuable insights into how leaders operate in established structures, they do not fully account for those who emerge from structural voids. Leaders out of necessity do not wait for the baton to be passed; they act because inaction is no longer an option. These leaders—often found in families, grassroots movements, startups, and marginalized communities—embody the FIRE framework: Foresight, Initiative, Resilience, and Execution. The culmination of this model is the figure of the hustlepreneur: a self-made, execution-focused leader who turns handicaps into assets. By centering the analysis on necessity, rather than position, this chapter contributes to a broader understanding of leadership legitimacy, emergence, and adaptability in dynamic contexts.