A proton conductive hydrogen-bonded organic framework (HOF) was constructed from a C3-symmetric hexatopic carboxylic acid derivative with an 18-crown-6-ether component. Despite the flexibility of the macrocycle, H-bonding modules allow the derivative to yield a hexagonally networked framework with permanent porosity. As reported by Takayoshi Nakamura, Ichiro Hisaki, and co-workers in their Communication (e202211686), the HOF possesses 1D channels with a bottleneck composed of the macrocycles and shows proton conductivity (1.12×10−7 S cm−1) through the Grotthuss mechanism (Ea=0.27 eV) under 98 %RH.