The *circlize* package is introduced as a flexible and powerful tool for circular visualization in R, designed to enhance the efficiency and flexibility of genomic data visualization. Circular layouts are advantageous for representing large amounts of genomic information, particularly when dealing with long axes, multiple categories, and complex relationships. The package leverages low-level graphics functions to allow users to easily customize and create various types of circular plots, making it suitable for both basic and advanced visualizations. *circlize* supports seamless integration with R's computational and visualization environment, enabling automatic generation of circular designs and facilitating the creation of high-level packages for specific genomic analysis needs. The package is available on CRAN and can be used to visualize genomic data in a variety of ways, including scatter plots, heatmaps, and nested circular layouts. Examples and detailed documentation are provided to guide users through the process of creating circular layouts.The *circlize* package is introduced as a flexible and powerful tool for circular visualization in R, designed to enhance the efficiency and flexibility of genomic data visualization. Circular layouts are advantageous for representing large amounts of genomic information, particularly when dealing with long axes, multiple categories, and complex relationships. The package leverages low-level graphics functions to allow users to easily customize and create various types of circular plots, making it suitable for both basic and advanced visualizations. *circlize* supports seamless integration with R's computational and visualization environment, enabling automatic generation of circular designs and facilitating the creation of high-level packages for specific genomic analysis needs. The package is available on CRAN and can be used to visualize genomic data in a variety of ways, including scatter plots, heatmaps, and nested circular layouts. Examples and detailed documentation are provided to guide users through the process of creating circular layouts.