Sulfur resilient steam reforming catalysts are of great interest for the development of solid oxide fuel cell systems for aeronautic applications. We demonstrate that nickel–manganese catalysts exhibit substantially improved stability during steam reforming of sulfur containing fuels via a sulfur spillover strategy as compared to monometallic nickel catalysts. This is established via detailed deactivation studies of catalysts in steam reforming conditions with sulfur containing model fuels and real jet fuels (JP-8). Through detailed characterization of spent catalysts, we establish that the increased sulfur resilience is imparted by an increased sulfur capacity due to scavenging by manganese oxide species in close proximity to active nickel particles. Results presented in this work could pave the way for practical application of precious-metal-free steam reforming catalysts in sulfur rich streams, both in aeronautic SOFC systems and other applications.