Fe‐N‐C catalysts with high O2 reduction performance are crucial for displacing Pt in low‐temperature fuel cells. However, insufficient understanding of which reaction steps are catalyzed by what sites limits their progress. The nature of sites were investigated that are active toward H2O2 reduction, a key intermediate during indirect O2 reduction and a source of deactivation in fuel cells. Catalysts comprising different relative contents of FeNxCy moieties and Fe particles encapsulated in N‐doped carbon layers (0–100 %) show that both types of sites are active, although moderately, toward H2O2 reduction. In contrast, N‐doped carbons free of Fe and Fe particles exposed to the electrolyte are inactive. When catalyzing the ORR, FeNxCy moieties are more selective than Fe particles encapsulated in N‐doped carbon. These novel insights offer rational approaches for more selective and therefore more durable Fe‐N‐C catalysts. The chemical nature of secondary sites active for reduction of the H2O2 intermediate generated during indirect oxygen reduction was elucidated for the class of Fe‐N‐C catalysts. Both N‐doped carbon layers encapsulating Fe particles and FeNxCy moieties moderately catalyze H2O2 reduction, while Fe‐free N‐doped carbons and exposed Fe particles are inactive. Direct and indirect pathways for O2 reduction on Fe‐N‐C catalysts could thus be established.