This reference work is an important resource in the growing field of heroism studies. It presents concepts, research, and events key to understanding heroism, heroic leadership, heroism development, heroism science, and their relevant applications to businesses, organizations, clinical psychology, human wellness, human growth potential, public health, social justice, social activism, and the humanities. The encyclopedia emphasizes five key realms of theory and application: Business and organization, focusing on management effectiveness, emotional intelligence, empowerment, ethics, transformational leadership, product branding, motivation, employee wellness, entrepreneurship, and whistleblowers; clinical-health psychology and public health, focusing on stress and trauma, maltreatment, emotional distress, bullying, psychopathy, depression, anxiety, family disfunction, chronic illness, and healthcare workers’ wellbeing; human growth and positive psychology, discussing altruism, authenticity, character strengths, compassion, elevation, emotional agility, eudaimonia, morality, empathy, flourishing, flow, self-efficacy, joy, kindness, prospection, moral development, courage, and resilience; social justice and activism, highlighting anti-racism, anti-bullying, civil disobedience, civil rights heroes, climate change, environmental heroes, enslavement heroes, human rights heroism, humanitarian heroes, inclusivity, LGBTQ+ heroism, #metoo movement heroism, racism, sustainability, and women’s suffrage heroes; and humanities, relating to the mythic hero’s journey, bliss, boon, crossing the threshold, epic heroes, fairy tales, fiction, language and rhetoric, narratives, mythology, hero monomyth, humanities and heroism, religious heroes, and tragic heroes.