This article presents a method to achieve asymmetric transmission of left-handed and right-handed circularly polarized light in planar Fabry–Pérot (FP) microcavities using a 2D chiral microcavity based on apparent circular dichroism (ACD). The approach utilizes organic thin films with 2D chirality, which exhibit ACD, to induce asymmetric transmission without requiring nanofabrication. The ACD effect arises from the 2D chirality of the material, leading to a significant enhancement of the chiroptical response in the microcavity. The study demonstrates that the 2D chiral microcavity can achieve a chiroptical response up to 10 times larger than that of the isolated thin film. The results show that the microcavity enhances the chiroptical response by amplifying the ACD signal through increased optical pathlength. The study also highlights the spatial, spectral, and angular chiroptical responses of the 2D chiral microcavity. The research provides a simple and effective method for creating 2D chiral microcavities, which can be used in various applications such as spintronics, polaritronics, and chiral lasing. The findings demonstrate the potential of 2D chiral microcavities for quantum information science and other applications requiring asymmetric light-matter interactions. The study also discusses the differences between 2D and 3D chiral microcavities and the implications of the observed chiroptical responses. The results show that the 2D chiral microcavity can be easily produced by spin coating an organic thin film onto a mirror, making it a promising approach for creating chiral microcavities without the need for complex nanofabrication techniques. The study also highlights the potential of ACD for applications in quantum information processing and the directional manipulation of light. The research provides a new method for achieving asymmetric transmission in microcavities, which could lead to advancements in quantum technologies and optical devices.This article presents a method to achieve asymmetric transmission of left-handed and right-handed circularly polarized light in planar Fabry–Pérot (FP) microcavities using a 2D chiral microcavity based on apparent circular dichroism (ACD). The approach utilizes organic thin films with 2D chirality, which exhibit ACD, to induce asymmetric transmission without requiring nanofabrication. The ACD effect arises from the 2D chirality of the material, leading to a significant enhancement of the chiroptical response in the microcavity. The study demonstrates that the 2D chiral microcavity can achieve a chiroptical response up to 10 times larger than that of the isolated thin film. The results show that the microcavity enhances the chiroptical response by amplifying the ACD signal through increased optical pathlength. The study also highlights the spatial, spectral, and angular chiroptical responses of the 2D chiral microcavity. The research provides a simple and effective method for creating 2D chiral microcavities, which can be used in various applications such as spintronics, polaritronics, and chiral lasing. The findings demonstrate the potential of 2D chiral microcavities for quantum information science and other applications requiring asymmetric light-matter interactions. The study also discusses the differences between 2D and 3D chiral microcavities and the implications of the observed chiroptical responses. The results show that the 2D chiral microcavity can be easily produced by spin coating an organic thin film onto a mirror, making it a promising approach for creating chiral microcavities without the need for complex nanofabrication techniques. The study also highlights the potential of ACD for applications in quantum information processing and the directional manipulation of light. The research provides a new method for achieving asymmetric transmission in microcavities, which could lead to advancements in quantum technologies and optical devices.