Emotional intelligence (EI) is increasingly recognised as a critical component of effective school leadership, yet its practical role in shaping leadership outcomes remains underexplored, particularly within the Irish post-primary context. This study investigates how emotions influence leadership practices and outcomes, focusing on school leaders’ perceptions of EI and its integration into leadership styles. The research aims to examine the interplay between emotional intelligence, emotional labour, and leadership effectiveness, and to identify strategies for embedding EI within leadership development. A qualitative design was adopted, employing semi-structured interviews with ten senior leaders (principals and deputy principals) from diverse post-primary schools in Ireland. Data were analysed thematically using Braun and Clarke’s six-step framework. Four overarching themes emerged: Emotional Intelligence, Emotional Labour, Emotion Management, and Leadership Style. Participants demonstrated a nuanced understanding of EI, emphasising empathy, self-awareness, and relationship-building as central to effective leadership. Emotional labour and display rules were identified as significant challenges, particularly during crises. Authenticity and trust were highlighted as essential for fostering positive school cultures. Transformational leadership was frequently cited as an aspirational style, strongly linked to high EI. The findings underscore the pivotal role of emotional intelligence in navigating the complexities of school leadership. Leaders who effectively manage emotions and lead with authenticity are better equipped to create inclusive, resilient, and high-performing school environments. The study advocates for the integration of EI training into leadership preparation and continuous professional development, alongside mentoring and coaching initiatives.