Styled Components is a popular library for styling React applications. It allows developers to write CSS directly within their JavaScript files, creating components that are styled using tagged template literals. This approach helps to keep styles scoped to individual components, preventing conflicts and making it easier to manage styles in large applications. By using Styled Components, developers can create dynamic styles based on component props, enabling more flexible and reusable design patterns. The library also supports theming, allowing for consistent styling across an application while making it easy to switch themes or adjust styles globally.