The CircStat toolbox is a MATLAB package designed for the statistical analysis of circular and directional data. Circular data, such as angles, directions, or time of day, cannot be analyzed using standard linear statistical methods due to their circular nature. CircStat provides functions for both descriptive and inferential statistics, including measures of central tendency, spread, symmetry, and peakedness. It also includes tests for circular uniformity, such as the Rayleigh test, and methods for comparing mean and median directions across multiple samples. The toolbox supports both parametric and non-parametric tests, including one- and two-factor ANOVA for circular data. Additionally, CircStat includes functions for calculating circular-circular and circular-linear correlations, as well as the von Mises distribution, which is a common model for circular data. The toolbox is demonstrated using neurophysiological data to analyze orientation tuning in neurons. The CircStat toolbox aims to make circular statistics accessible to a broader audience, particularly in biomedical research.The CircStat toolbox is a MATLAB package designed for the statistical analysis of circular and directional data. Circular data, such as angles, directions, or time of day, cannot be analyzed using standard linear statistical methods due to their circular nature. CircStat provides functions for both descriptive and inferential statistics, including measures of central tendency, spread, symmetry, and peakedness. It also includes tests for circular uniformity, such as the Rayleigh test, and methods for comparing mean and median directions across multiple samples. The toolbox supports both parametric and non-parametric tests, including one- and two-factor ANOVA for circular data. Additionally, CircStat includes functions for calculating circular-circular and circular-linear correlations, as well as the von Mises distribution, which is a common model for circular data. The toolbox is demonstrated using neurophysiological data to analyze orientation tuning in neurons. The CircStat toolbox aims to make circular statistics accessible to a broader audience, particularly in biomedical research.