The article provides a comprehensive review of the science and history of stratospheric ozone depletion, focusing on the role of chlorofluorocarbons (CFCs) and the catalytic chemistry involved. It begins with a brief history of ozone depletion research, highlighting the recognition of ozone's importance in absorbing solar ultraviolet radiation and its impact on Earth's climate and life. The article then delves into the gas phase chemistry, explaining how CFCs break down in the stratosphere to release chlorine and bromine atoms, which initiate catalytic cycles that destroy ozone. The partitioning of chlorine between active forms that destroy ozone (Cl, ClO) and inert reservoirs (HCl, ClONO2) is a central concept, with the latter sequestering chlorine and reducing its availability for ozone destruction. The article discusses the discovery and verification of the Antarctic ozone hole, emphasizing the seasonal and latitudinal patterns of ozone depletion. It explains how the formation of polar stratospheric clouds (PSCs) in the Antarctic lower stratosphere, particularly at cold temperatures, facilitates the heterogeneous chemistry that accelerates ozone loss. The role of PSCs in perturbing gas phase chlorine partitioning and the suppression of nitrogen oxides (NOx) is highlighted. Early theoretical studies and observations supporting these mechanisms are reviewed, including the "cliff" in NOx observed by Noxon, which later explained the rapid ozone loss in the ozone hole. The article also addresses the challenges and limitations of various theories proposed to explain the ozone hole, such as dynamical and solar theories, and emphasizes the importance of heterogeneous chemistry in the Antarctic ozone depletion process. It concludes by discussing the expected gradual recovery of the ozone layer as global emissions of CFCs decrease, along with the need for continued monitoring and research to understand and mitigate future ozone depletion.The article provides a comprehensive review of the science and history of stratospheric ozone depletion, focusing on the role of chlorofluorocarbons (CFCs) and the catalytic chemistry involved. It begins with a brief history of ozone depletion research, highlighting the recognition of ozone's importance in absorbing solar ultraviolet radiation and its impact on Earth's climate and life. The article then delves into the gas phase chemistry, explaining how CFCs break down in the stratosphere to release chlorine and bromine atoms, which initiate catalytic cycles that destroy ozone. The partitioning of chlorine between active forms that destroy ozone (Cl, ClO) and inert reservoirs (HCl, ClONO2) is a central concept, with the latter sequestering chlorine and reducing its availability for ozone destruction. The article discusses the discovery and verification of the Antarctic ozone hole, emphasizing the seasonal and latitudinal patterns of ozone depletion. It explains how the formation of polar stratospheric clouds (PSCs) in the Antarctic lower stratosphere, particularly at cold temperatures, facilitates the heterogeneous chemistry that accelerates ozone loss. The role of PSCs in perturbing gas phase chlorine partitioning and the suppression of nitrogen oxides (NOx) is highlighted. Early theoretical studies and observations supporting these mechanisms are reviewed, including the "cliff" in NOx observed by Noxon, which later explained the rapid ozone loss in the ozone hole. The article also addresses the challenges and limitations of various theories proposed to explain the ozone hole, such as dynamical and solar theories, and emphasizes the importance of heterogeneous chemistry in the Antarctic ozone depletion process. It concludes by discussing the expected gradual recovery of the ozone layer as global emissions of CFCs decrease, along with the need for continued monitoring and research to understand and mitigate future ozone depletion.