Abstract: | Organic–inorganic lead halides have recently emerged as promising alternatives to conventional optoelectronic materials, considering their intriguing physical properties. However, organic–inorganic lead halides featuring chirality are seldom explored. Here, a pair of enantiomorphic organic–inorganic hybrid semiconducting lead halides, (R‐C5H14N2)PbBr4 ( 1R ) and (S‐C5H14N2)PbBr4 ( 2S ), were successfully obtained with the templating of chiral amines. These compounds adopt distinct one‐dimensional infinite quantum helices formed by edge‐shared transformative lead bromide octahedra. Notably, 1R and 2S present mirror circular dichroism (CD) signals due to the chirality transfer of the enantiopure amines. Furthermore, 1R and 2S exhibit phase‐matchable quadratic nonlinear response and typical semiconducting behaviours. This work highlights the potential of lead halides as a new kind of chiral semiconducting materials in spintronic and chiral optical applications. |