Using CSS (Cascading Style Sheets) in web design offers multiple benefits, primarily enhancing the visual presentation of a website. CSS separates content from design, allowing developers to maintain styles in one place and apply them across multiple pages, ensuring consistency. It also enhances website loading times and performance by enabling stylesheet caching. Furthermore, CSS supports responsive design principles, allowing web pages to adapt to different screen sizes and devices seamlessly. Overall, it contributes to a better user experience by making websites more aesthetically pleasing and user-friendly.