Military and sport have attracted increased research interest separately as two distinctly demanding performance- and leadership-driven contexts. However, cross-contextual psychological research in leadership is lacking. Such research has potential to expose unique cross-fertilising insights into resemblances in leadership challenges among military and sport leaders, transferable to a broader range of contexts. Thus, the current study simultaneously explored high-level military and sport leaders’ real-life experiences of similarities in demanding conditions and their psychological manifestations. Sixteen participants - eight Swedish high-level military leaders and eight Swedish high-level sport leaders, participated in the study. Using a qualitative inductive cross-contextual design enabled in-depth knowledge and transferability. A reflexive thematic analysis (RTA) of sixteen interview transcripts generated four common themes of demanding conditions: (1) Developing organisations: Leading under an extensive workload and responsibility, (2) Managing destructive superiors and subordinates: Standing up for oneself, (3) Taking care of the minds and moods of others: Leading deliberated difficult conversations, and (4) Periods of extreme concentration: Leading critical coordination, decisions, and timing. The findings tie high-level military and sports leaders together into a high-stress and high-stakes leader role invoked to manoeuvre a complex buildup of demanding conditions. Implications are presented.