Metal‐organic frameworks (MOFs) nanoparticles in combination with a nonionic surfactant (Pluronic L‐121) are used to stabilize dicyclopentadiene (DCPD)‐in‐water high internal phase emulsions (HIPEs). The resulting HIPEs containing the MIL‐100(Fe) nanoparticles (MIL: Materials of Institut Lavoisier) at the interface between the oil‐ and the water‐phases are then cured, and 100 μm thick, fully open, hierarchically porous hybrid membranes are obtained. The properties of the MIL‐100(Fe)@pDCPD polyHIPE membranes are characterized and it is found that up to 14 wt% of the MIL‐100(Fe) nanoparticles are incorporated in the hybrid material resulting in an increase of the microporosity up to 130 m2 g−1. Hybrid membranes show an appealing catalytic activity in Friedel–Crafts alkylation in a batch mode as well as in a flow‐through mode, thereby demonstrating the preserved accessibility of Lewis acidic sites in the MOF nanostructures.